Condition

Immune Health

Your immune system is a network of white blood cells, antibodies, and signaling molecules that defend the body against germs, and it works less well when nutrients run short. Vitamin D and zinc have the strongest evidence behind them, while elderberry trials found colds lasted a shorter time and felt milder. That elderberry evidence is moderate and comes from small studies, and other compounds, like luteolin, have mostly been tested in lab work.

Sources: PMID 30670267

Supplements studied: 55
Medicines and peptides: 1
Graded outcomes: 54
Trials: 123
People studied: 19,979

Evidence by supplement

Strong
Moderate
Limited
Very limited

55 supplements

Boron

Boron: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People
	C-Reactive Protein (CRP) Moderate Decrease	Improves (the measure goes down)	Moderate effect	3 studies	178 people
Studies that measured c-reactive protein (crp) The adjuvant use of calcium fructoborate and borax with etanercept in patients with rheumatoid arthritis: Pilot studyJ Intercult Ethnopharmacol · PMID 28163961 Effects of Calcium Fructoborate on Levels of C-Reactive Protein, Total Cholesterol, Low-Density Lipoprotein, Triglycerides, IL-1β, IL-6, and MCP-1: a Double-blind, Placebo-controlled Clinical StudyBiol Trace Elem Res · PMID 25433580 Comparative effects of daily and weekly boron supplementation on plasma steroid hormones and proinflammatory cytokinesJ Trace Elem Med Biol · PMID 21129941
	Blood glucose No effect		NoneNo effect		90 people
	Estrogen	Changes; see studies		1 study	8 people
Studies that measured estrogen Effect of dietary boron on mineral, estrogen, and testosterone metabolism in postmenopausal womenFASEB J · PMID 3678698
	Testosterone	Improves (the measure goes up)		1 study	8 people
Studies that measured testosterone Plasma boron and the effects of boron supplementation in malesEnviron Health Perspect · PMID 7889885
	Triglycerides	Changes; see studies		1 study	90 people
Studies that measured triglycerides Oral resveratrol and calcium fructoborate supplementation in subjects with stable angina pectoris: effects on lipid profiles, inflammation markers, and quality of lifeNutrition · PMID 23153742
	Cortisol	Changes; see studies			8 people
	DHT	Improves (the measure goes up)			8 people
	Erythrocyte Sedimentation Rate	Changes; see studies			80 people
	Free Testosterone	Improves (the measure goes up)			8 people
	High-density lipoprotein (HDL)	Improves (the measure goes up)			90 people
	Inflammation	Changes; see studies			8 people
	Interleukin 1-alpha	Improves (the measure goes up)			80 people
	Interleukin 1-beta	Changes; see studies			90 people
	Interleukin 6	Changes; see studies			170 people
	Low-density lipoprotein (LDL)	Changes; see studies			90 people
	Monocyte Chemoattractant Protein-1	Improves (the measure goes up)			90 people
	Rheumatoid Arthritis Symptoms	Changes; see studies			80 people
	TNF-Alpha	Changes; see studies			80 people

Andrographis

Andrographis: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	CD4+ Count Significant increase in CD4+ counts; enhanced NK cell cytotoxicity (45%)	Improves (the measure goes up)	Moderate effect		30 people

Triphala (Emblica officinalis, Terminalia chebula, Terminalia bellirica)

Antioxidant Status: improves

Triphala (Emblica officinalis, Terminalia chebula, Terminalia bellirica): outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Antioxidant Status Phase I clinical study in healthy volunteers: Triphala supplementation significantly increased SOD activity and decreased MDA and protein carbonyl concentrations. Rich in vitamin C, gallic acid, ellagic acid, and flavonoids. Free radical-scavenging activity comparable to ascorbic acid.	Improves (the measure goes up)	Moderate effect

Lactoferrin

Inflammation Markers: improves

Lactoferrin: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Inflammation Markers Moderate Decrease	Improves (the measure goes down)	Moderate effect		1,200 people

Luteolin

Mast Cell Inhibition: improves

Luteolin: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Mast Cell Inhibition In vitro studies: Luteolin significantly more potent than cromolyn (standard mast cell stabilizer) at inhibiting release of histamine, tryptase, MMP-9, VEGF, IL-1β, IL-6, IL-8, and TNF from human mast cells. Effective at concentrations achievable with oral supplementation.	Improves (the measure goes up)	Large effect

N-Acetylcysteine

COPD Symptoms: improves
Neutrophil Activity: improves

N-Acetylcysteine: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People
	COPD Symptoms Small Improvement	Improves (the measure goes down)	Small effect	5 studies	20 people
Studies that measured copd symptoms New developments in the treatment of COPD: comparing the effects of inhaled corticosteroids and N-acetylcysteineJ Physiol Pharmacol · PMID 16204787 Systematic review and meta-analysis of the efficacy of N-acetylcysteine in the treatment of acute exacerbation of chronic obstructive pulmonary disease.Ann Palliat Med · PMID 34237968 Effects of N-acetylcysteine on outcomes in chronic obstructive pulmonary disease (Bronchitis Randomized on NAC Cost-Utility Study, BRONCUS): a randomised placebo-controlled trialLancet · PMID 15866309 and 2 more on the N-Acetylcysteine page
	Neutrophil Activity	Improves (the measure goes up)		1 study	50 people
Studies that measured neutrophil activity Induced sputum of patients with chronic obstructive pulmonary disease (COPD) contains adhesion-promoting, therapy-sensitive factorsInflamm Res · PMID 10778915

Vitamin C

Blood glucose: improves
Upper Respiratory Tract Infection Symptoms: improves
Cortisol: improves

Vitamin C: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People
	Blood glucose Small Improvement	Improves (the measure goes down)	Small effect	3 studies	28 people
Studies that measured blood glucose High-dose oral vitamin C partially replenishes vitamin C levels in patients with Type 2 diabetes and low vitamin C levels but does not improve endothelial dysfunction or insulin resistanceAm J Physiol Heart Circ Physiol · PMID 16126809 Megadose of vitamin C delays insulin response to a glucose challenge in normoglycemic adultsAm J Clin Nutr · PMID 7942581 FFA-induced endothelial dysfunction can be corrected by vitamin CJ Clin Endocrinol Metab · PMID 12050273
	Upper Respiratory Tract Infection Symptoms	Improves (the measure goes down)		24 studies	474 people
Studies that measured upper respiratory tract infection symptoms Vitamin C and the common cold: a double-blind trialCan Med Assoc J · PMID 5057006 Ascorbic acid and the common coldLancet · PMID 4113614 Preventing the common cold with a vitamin C supplement: a double-blind, placebo-controlled surveyAdv Ther · PMID 12201356 and 21 more on the Vitamin C page
	Cortisol	Improves (the measure goes down)		5 studies	93 people
Studies that measured cortisol The effect of 2 weeks vitamin C supplementation on immunoendocrine responses to 2.5 h cycling exercise in manEur J Appl Physiol · PMID 16685547 Vitamin C supplementation and salivary immune function following exercise-heat stressInt J Sports Physiol Perform · PMID 19223675 Influence of vitamin C supplementation on oxidative and salivary IgA changes following an ultramarathonEur J Appl Physiol · PMID 12627313 and 2 more on the Vitamin C page
	Oxidative Stress Biomarkers	Improves (the measure goes down)		5 studies	56 people
Studies that measured oxidative stress biomarkers Vitamin C supplementation lowers urinary levels of 4-hydroperoxy-2-nonenal metabolites in humansFree Radic Biol Med · PMID 21236333 High dosage of ascorbic acid and alpha-tocopherol is not useful for diminishing oxidative stress and DNA damage in healthy elderly adultsAnn Nutr Metab · PMID 18446021 Orange juice ingestion and supplemental vitamin C are equally effective at reducing plasma lipid peroxidation in healthy adult womenJ Am Coll Nutr · PMID 14684757 and 2 more on the Vitamin C page
	Upper Respiratory Tract Infection Risk	Changes; see studies		5 studies	1,159 people
Studies that measured upper respiratory tract infection risk Vitamin C supplementation reduces the odds of developing a common cold in Republic of Korea Army recruits: randomised controlled trialBMJ Mil Health · PMID 32139409 The effects of ascorbic acid and flavonoids on the occurrence of symptoms normally associated with the common coldAm J Clin Nutr · PMID 463806 The clinical and biochemical effects of vitamin C supplementation in short-stay hospitalized geriatric patientsInt J Vitam Nutr Res · PMID 6376396 and 2 more on the Vitamin C page
	Exercise-Induced Oxidation	Changes; see studies		2 studies	16 people
	Inflammation	Improves (the measure goes down)		2 studies	30 people
	Muscle Damage	Changes; see studies		2 studies	30 people
	Uric Acid	Improves (the measure goes down)		2 studies	28 people
	Heart Rate	Improves (the measure goes down)		1 study	40 people
	Interferon Gamma	Improves (the measure goes up)		1 study	28 people
	Plasma Vitamin C	Improves (the measure goes up)		1 study	56 people
	Exercise-Induced Immune Suppression	Improves (the measure goes up)			93 people
	IL-1Ra	Improves (the measure goes down)			28 people
	Insulin	Changes; see studies			28 people
	Interleukin 10	Improves (the measure goes up)			28 people
	Interleukin 2	Improves (the measure goes up)			28 people
	Interleukin 6	Improves (the measure goes down)			28 people
	Interleukin 8	Changes; see studies			28 people
	Lymphocyte Count	Improves (the measure goes up)			28 people
	Monocyte Count	Improves (the measure goes up)			28 people
	Natural Killer Cell Content	Improves (the measure goes up)			28 people
	Neutrophil Count	Improves (the measure goes up)			28 people

Theanine

Anxiety Symptoms: improves
Heart Rate: improves
Interleukin 4: improves

Theanine: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People
	Anxiety Symptoms Small Improvement	Improves (the measure goes down)	Small effect	2 studies	12 people
Studies that measured anxiety symptoms L-Theanine reduces psychological and physiological stress responsesBiol Psychol · PMID 16930802 The Effects of Green Tea Amino Acid L-Theanine Consumption on the Ability to Manage Stress and Anxiety Levels: a Systematic Review.Plant Foods Hum Nutr · PMID 31758301
	Heart Rate	Improves (the measure goes down)		1 study	12 people
Studies that measured heart rate The Effect of L-Theanine Incorporated in a Functional Food Product (Mango Sorbet) on Physiological Responses in Healthy Males: A Pilot Randomised Controlled TrialFoods · 2020 · PMID 32210015
	Interleukin 4	Improves (the measure goes up)		1 study	20 people
Studies that measured interleukin 4 The effect of L-theanine supplementation on the immune system of athletes exposed to strenuous physical exerciseJ Int Soc Sports Nutr · PMID 30770758
	Stress Signs and Symptoms	Improves (the measure goes down)		1 study	12 people
Studies that measured stress signs and symptoms Safety and Efficacy of AlphaWave(®) L-Theanine Supplementation for 28 Days in Healthy Adults with Moderate Stress: A Randomized, Double-Blind, Placebo-Controlled Trial.Neurol Ther · PMID 38758503
	Granulocyte Count	Improves (the measure goes up)			20 people
	Interferon Gamma	Improves (the measure goes up)			20 people
	Interleukin 10	Improves (the measure goes up)			20 people
	Interleukin 2	Improves (the measure goes up)			20 people
	Lymphocyte Count	Improves (the measure goes up)			20 people
	Natural Killer Cell Content	Improves (the measure goes up)			20 people
	Total Antioxidant Capacity (TAC)	Improves (the measure goes up)			20 people
	Treg Cells	Improves (the measure goes up)			20 people
	White Blood Cell Count	Improves (the measure goes up)			20 people

Cat's claw

White Blood Cell Count: improves

Cat's claw: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	White Blood Cell Count Small Increase	Improves (the measure goes up)	Small effect	1 study	4 people
Studies that measured white blood cell count Enhanced DNA repair, immune function and reduced toxicity of C-MED-100, a novel aqueous extract from Uncaria tomentosaJ Ethnopharmacol · PMID 10687868

Iodine

C-Reactive Protein (CRP): improves
Interleukin 6: improves

Iodine: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People
	C-Reactive Protein (CRP) Small Decrease	Improves (the measure goes down)	Small effect	1 study	30 people
Studies that measured c-reactive protein (crp) Iodine intakes of 100-300 μg/d do not modify thyroid function and have modest anti-inflammatory effectsBr J Nutr · PMID 21262066
	Interleukin 6	Improves (the measure goes down)			30 people

Reishi

CD3 Lymphocytes: improves
CD4 Lymphocytes: improves
Immunity: improves

Reishi: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People
	CD3 Lymphocytes Small Increase	Improves (the measure goes up)	Small effect	1 study	40 people
Studies that measured cd3 lymphocytes Effect of Ganoderma lucidum capsules on T lymphocyte subsets in football players on "living high-training low"Br J Sports Med · PMID 18048435
	CD4 Lymphocytes Small Increase	Improves (the measure goes up)	Small effect		40 people
	Immunity	Improves (the measure goes up)		3 studies	97 people
Studies that measured immunity Monitoring of immune responses to a herbal immuno-modulator in patients with advanced colorectal cancerInt Immunopharmacol · PMID 16428086 Safety and tolerability of Ganoderma lucidum in healthy subjects: a double-blind randomized placebo-controlled trialAm J Chin Med · PMID 17597499 Effects of ganopoly (a Ganoderma lucidum polysaccharide extract) on the immune functions in advanced-stage cancer patientsImmunol Invest · PMID 12916709
	Proteinuria	Improves (the measure goes up)		1 study	14 people
Studies that measured proteinuria Ganoderma lucidum suppresses endothelial cell cytotoxicity and proteinuria in persistent proteinuric focal segmental glomerulosclerosis (FSGS) nephrosisClin Hemorheol Microcirc · PMID 15567896
	Natural Killer Cell Activity	Improves (the measure goes up)			34 people
	TNF-Alpha	Improves (the measure goes down)			34 people

Glutathione

Anti-Oxidant Enzyme Profile: improves
Natural Killer Cell Activity: improves

Glutathione: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People
	Anti-Oxidant Enzyme Profile Moderate Increase	Improves (the measure goes up)	Moderate effect	1 study	52 people
Studies that measured anti-oxidant enzyme profile Randomized controlled trial of oral glutathione supplementation on body stores of glutathioneEur J Nutr · PMID 24791752
	Natural Killer Cell Activity Small Increase	Improves (the measure goes up)	Small effect		52 people

Saffron

Basophil Count: improves
Blood glucose: improves
Creatinine: improves

Saffron: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
Basophil Count Small Decrease	Improves (the measure goes down)	Small effect		89 people
Blood glucose	Improves (the measure goes down)		6 studies	64 people
Creatinine	Improves (the measure goes up)		2 studies	89 people
TNF-Alpha	Improves (the measure goes down)		2 studies	64 people
C-Reactive Protein (CRP)	Improves (the measure goes down)		1 study	64 people
Liver Enzymes	Changes; see studies		1 study	89 people
Oxidative Stress Biomarkers	Improves (the measure goes down)		1 study	64 people
Eosinophil count	Changes; see studies			89 people
HbA1c	Improves (the measure goes down)			64 people
Immunoglobulin A	Improves (the measure goes up)			89 people
Immunoglobulin G	Improves (the measure goes up)			89 people
Immunoglobulin M	Improves (the measure goes up)			89 people
Interleukin 10	Improves (the measure goes up)			64 people
Interleukin 6	Improves (the measure goes down)			64 people
Monocyte Count	Improves (the measure goes up)			89 people
Neutrophil Count	Improves (the measure goes up)			89 people
Red Blood Cell Count	Improves (the measure goes up)			89 people
Total Antioxidant Capacity (TAC)	Improves (the measure goes up)			64 people
White Blood Cell Count	Improves (the measure goes up)			89 people

Fish Oil

5-HEPE: improves
Triglycerides: improves
High-density lipoprotein (HDL): improves

Fish Oil: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
5-HEPE Moderate Increase	Improves (the measure goes up)	Moderate effect		50 people
Triglycerides	Improves (the measure goes down)		24 studies	135 people
High-density lipoprotein (HDL)	Improves (the measure goes up)		7 studies	135 people
C-Reactive Protein (CRP)	Improves (the measure goes down)		4 studies	221 people
Inflammation	Improves (the measure goes down)		4 studies	276 people
Cortisol	Improves (the measure goes down)		2 studies	61 people
TNF-Alpha	Improves (the measure goes down)		2 studies	63 people
Vascular Function	Improves (the measure goes up)		2 studies	25 people
5-HETE	Improves (the measure goes up)		1 study	50 people
Blood Flow	Improves (the measure goes up)		1 study	25 people
Exercise-Induced Immune Suppression	Improves (the measure goes up)		1 study	16 people
Interleukin 2	Improves (the measure goes up)		1 study	16 people
Leukotriene B5	Improves (the measure goes up)		1 study	50 people
Low-density lipoprotein (LDL)	Improves (the measure goes down)		1 study	110 people
Natural Killer Cell Content	Improves (the measure goes up)		1 study	155 people
Oxidative Stress Biomarkers	Improves (the measure goes down)		1 study	46 people
T Cell Count	Improves (the measure goes up)		1 study	185 people
B Cell Count	Improves (the measure goes up)			139 people
Leukotriene B4	Improves (the measure goes up)			50 people
Lymphocyte Count	Improves (the measure goes up)			25 people
Natural Killer Cell Activity	Improves (the measure goes up)			139 people
Oxygen Uptake	Improves (the measure goes up)			16 people

Guduchi

Allergy Symptoms: improves
Eosinophil count: changes; see studies
Lymphocyte Count: improves

Guduchi: outcomes studied for Immune Health
Outcome	Effect	Size	People
Allergy Symptoms Large Improvement	Improves (the measure goes down)	Large effect	75 people
Eosinophil count	Changes; see studies		75 people
Lymphocyte Count	Improves (the measure goes up)		150 people
Nasal Congestion	Improves (the measure goes up)		75 people
Neutrophil Count	Improves (the measure goes up)		75 people

Lactobacillus Casei

C-Reactive Protein (CRP): improves
Blood glucose
Immunoglobulin A: improves

Lactobacillus Casei: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
C-Reactive Protein (CRP) Small Increase	Improves (the measure goes down)	Small effect		28 people
Blood glucose No effect		NoneNo effect		28 people
Immunoglobulin A	Improves (the measure goes up)		2 studies	84 people
Intestinal Permeability	Improves (the measure goes up)		1 study	28 people
Immunity	Improves (the measure goes up)			28 people
Immunoglobulin G	Improves (the measure goes up)			84 people
Triglycerides	Improves (the measure goes down)			28 people
Upper Respiratory Tract Infection Risk	Changes; see studies			84 people
White Blood Cell Count	Improves (the measure goes up)			84 people

Perilla

C-Reactive Protein (CRP): improves
Low-density lipoprotein (LDL): improves
High-density lipoprotein (HDL): improves

Perilla: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
C-Reactive Protein (CRP) Moderate Decrease	Improves (the measure goes down)	Moderate effect		36 people
Low-density lipoprotein (LDL)	Improves (the measure goes down)		1 study	36 people
High-density lipoprotein (HDL)	Improves (the measure goes up)			36 people
Liver Enzymes	Changes; see studies			36 people
Plasminogen Inhibitor-1	Improves (the measure goes up)			36 people
TNF-Alpha	Improves (the measure goes down)			36 people
Triglycerides	Improves (the measure goes down)			36 people

Umckaloabo

Exercise-Induced Immune Suppression: improves
Immunoglobulin A: improves

Umckaloabo: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Exercise-Induced Immune Suppression Small Improvement	Improves (the measure goes up)	Small effect		25 people
	Immunoglobulin A	Improves (the measure goes up)		1 study	25 people

Vitamin D

Body Fat: improves
Upper Respiratory Tract Infection Risk: changes; see studies
Upper Respiratory Tract Infection Symptoms: improves

Vitamin D: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
Body Fat Small Decrease	Improves (the measure goes down)	Small effect		165 people
Upper Respiratory Tract Infection Risk	Changes; see studies		13 studies	152 people
Upper Respiratory Tract Infection Symptoms	Improves (the measure goes down)		13 studies	68 people
Low-density lipoprotein (LDL)	Improves (the measure goes down)		3 studies	165 people
Interleukin 5	Improves (the measure goes up)		1 study	30 people
Parathyroid Hormone	Improves (the measure goes up)		1 study	165 people
Tuberculosis Symptoms	Improves (the measure goes down)		1 study	120 people
Metabolic Rate	Improves (the measure goes up)			165 people
TNF-Alpha	Improves (the measure goes down)			165 people
Triglycerides	Improves (the measure goes down)			165 people

Ashwagandha

Immunity: improves
Natural Killer Cell Activity: improves

Ashwagandha: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Immunity Small Improvement	Improves (the measure goes up)	Small effect		5 people
	Natural Killer Cell Activity	Improves (the measure goes up)		1 study	5 people

Echinacea

Exercise-Induced Immune Suppression: improves
Upper Respiratory Tract Infection Risk: changes; see studies
Upper Respiratory Tract Infection Symptoms: improves

Echinacea: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
Exercise-Induced Immune Suppression Small Improvement	Improves (the measure goes up)	Small effect		32 people
Upper Respiratory Tract Infection Risk	Changes; see studies		10 studies	32 people
Upper Respiratory Tract Infection Symptoms	Improves (the measure goes down)		1 study	32 people

Tulsi

Immunity: improves
Natural Killer Cell Content: improves

Tulsi: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Immunity Small Improvement	Improves (the measure goes up)	Small effect		24 people
	Natural Killer Cell Content	Improves (the measure goes up)		1 study	24 people

Spirulina

Anti-Oxidant Enzyme Profile: improves
Low-density lipoprotein (LDL): improves
Interleukin 6: improves

Spirulina: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
Anti-Oxidant Enzyme Profile Small Increase	Improves (the measure goes up)	Small effect		78 people
Low-density lipoprotein (LDL)	Improves (the measure goes down)		5 studies	128 people
Interleukin 6	Improves (the measure goes down)		3 studies	206 people
Total Antioxidant Capacity (TAC)	Improves (the measure goes up)		2 studies	50 people
Blood glucose	Improves (the measure goes down)		1 study	50 people
Interleukin 4	Improves (the measure goes up)		1 study	36 people
Natural Killer Cell Activity	Improves (the measure goes up)		1 study	21 people
Oxidative Stress Biomarkers	Improves (the measure goes down)		1 study	78 people
Treg Cells	Improves (the measure goes up)		1 study	19 people
Triglycerides	Improves (the measure goes down)		1 study	128 people
White Blood Cell Count	Improves (the measure goes up)		1 study	40 people
CD8 Lymphocytes	Improves (the measure goes up)			19 people
Complement Component 3	Improves (the measure goes up)			78 people
High-density lipoprotein (HDL)	Improves (the measure goes up)			128 people
Immunoglobulin A	Improves (the measure goes up)			78 people
Immunoglobulin G	Improves (the measure goes up)			78 people
Insulin	Changes; see studies			50 people
Insulin Resistance	Improves (the measure goes down)			50 people
Interferon Gamma	Improves (the measure goes up)			36 people
Interleukin 2	Improves (the measure goes up)			114 people
Monocyte Chemoattractant Protein-1	Improves (the measure goes up)			78 people
Natural Killer Cell Content	Improves (the measure goes up)			40 people
Red Blood Cell Count	Improves (the measure goes up)			40 people
T Cell Count	Improves (the measure goes up)			19 people
TNF-Alpha	Improves (the measure goes down)			156 people

L-Carnitine

Blood Flow: improves
Muscle Mass: improves
Oxidative Stress Biomarkers: improves

L-Carnitine: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
Blood Flow Small Increase	Improves (the measure goes up)	Small effect		30 people
Muscle Mass	Improves (the measure goes up)		3 studies	75 people
Oxidative Stress Biomarkers	Improves (the measure goes down)		3 studies	75 people
TNF-Alpha	Improves (the measure goes down)		2 studies	30 people
Body Fat	Improves (the measure goes down)		1 study	75 people
Myeloperoxidase	Improves (the measure goes up)		1 study	75 people
Total Antioxidant Capacity (TAC)	Improves (the measure goes up)			75 people

Black Ginger

Anti-Oxidant Enzyme Profile: improves
Functionality in Elderly or Injured: improves
Oxidative Stress Biomarkers: changes; see studies

Black Ginger: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
Anti-Oxidant Enzyme Profile Moderate Increase	Improves (the measure goes up)	Moderate effect		45 people
Functionality in Elderly or Injured	Improves (the measure goes up)		1 study	45 people
Oxidative Stress Biomarkers	Changes; see studies			45 people

Guduchi

Allergy Symptoms: improves
Lymphocyte Count: improves
Eosinophil count: changes; see studies

Guduchi: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
Allergy Symptoms Large Improvement	Improves (the measure goes down)	Large effect		75 people
Lymphocyte Count	Improves (the measure goes up)		1 study	150 people
Eosinophil count	Changes; see studies			75 people
Nasal Congestion	Improves (the measure goes up)			75 people
Neutrophil Count	Improves (the measure goes up)			75 people

Curcumin

Anti-Oxidant Enzyme Profile: improves
Blood glucose: improves
Triglycerides: improves

Curcumin: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
Anti-Oxidant Enzyme Profile Moderate Increase	Improves (the measure goes up)	Moderate effect		38 people
Blood glucose	Improves (the measure goes down)		18 studies	3,048 people
Triglycerides	Improves (the measure goes down)		9 studies	3,364 people
Oxidative Stress Biomarkers	Improves (the measure goes down)		6 studies	38 people
Liver Enzymes	Changes; see studies		3 studies	1,329 people
Interleukin 6	Improves (the measure goes down)		1 study	1,005 people
Body Mass Index (BMI)	Improves (the measure goes down)			2,789 people
C-Reactive Protein (CRP)	Improves (the measure goes down)			1,716 people
Cell Adhesion Factors	Improves (the measure goes down)			38 people
HbA1c	Improves (the measure goes down)			1,196 people
Myeloperoxidase	Improves (the measure goes up)			38 people
Nitric Oxide	Improves (the measure goes up)			38 people
TNF-Alpha	Improves (the measure goes down)			1,025 people
Total Antioxidant Capacity (TAC)	Improves (the measure goes up)			529 people

Eleuthero

Fat Oxidation: improves
Heart Rate
Natural Killer Cell Content: improves

Eleuthero: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
Fat Oxidation Small Increase	Improves (the measure goes up)	Small effect		31 people
Heart Rate No effect		NoneNo effect	1 study	31 people
Natural Killer Cell Content	Improves (the measure goes up)		1 study	31 people
Immunity	Improves (the measure goes up)			62 people
Oxygen Uptake	Improves (the measure goes up)			31 people

Astaxanthin

B Cell Count: worsens
C-Reactive Protein (CRP): changes; see studies
Oxidative Stress Biomarkers: changes; see studies

Astaxanthin: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
B Cell Count Small Decrease	Worsens (the measure goes down)	Small effect		42 people
C-Reactive Protein (CRP)	Changes; see studies		5 studies	82 people
Oxidative Stress Biomarkers	Changes; see studies		3 studies	40 people
Triglycerides	Changes; see studies		2 studies	69 people
Blood glucose	Changes; see studies		1 study	35 people
Eosinophil count	Changes; see studies		1 study	35 people
High-density lipoprotein (HDL)	Improves (the measure goes up)		1 study	69 people
Inflammation	Changes; see studies		1 study	44 people
Liver Enzymes	Changes; see studies		1 study	104 people
Lymphocyte Count	Improves (the measure goes up)		1 study	64 people
Basophil Count	Improves (the measure goes up)			35 people
Bilirubin	Changes; see studies			35 people
DNA Damage	Changes; see studies			71 people
Estrogen	Changes; see studies			29 people
Fibrinogen	Improves (the measure goes up)			29 people
Hematocrit	Improves (the measure goes up)			35 people
Hemoglobin	Improves (the measure goes up)			35 people
Interferon Gamma	Improves (the measure goes up)			42 people
Interleukin 2	Improves (the measure goes up)			42 people
Interleukin 6	Changes; see studies			42 people
Low-density lipoprotein (LDL)	Changes; see studies			69 people
Monocyte Count	Improves (the measure goes up)			35 people
Muscle Damage	Changes; see studies			35 people
Natural Killer Cell Activity	Improves (the measure goes up)			42 people
Natural Killer Cell Content	Improves (the measure goes up)			42 people
Neutrophil Count	Improves (the measure goes up)			64 people
Red Blood Cell Count	Improves (the measure goes up)			35 people
Serum Albumin	Improves (the measure goes up)			35 people
Serum Platelets	Improves (the measure goes up)			35 people
T Cell Count	Improves (the measure goes up)			42 people
TNF-Alpha	Changes; see studies			42 people
Total Antioxidant Capacity (TAC)	Improves (the measure goes up)			69 people
Uric Acid	Changes; see studies			40 people
White Blood Cell Count	Improves (the measure goes up)			64 people

Rose Hip

C-Reactive Protein (CRP)
Chemotaxis: changes; see studies
Liver Enzymes: changes; see studies

Rose Hip: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
C-Reactive Protein (CRP) No effect		NoneNo effect	3 studies	13 people
Chemotaxis	Changes; see studies			13 people
Liver Enzymes	Changes; see studies			13 people

King of Bitters

CD4 Lymphocytes
Early Virologic Response: improves
Liver Enzymes: changes; see studies

King of Bitters: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
CD4 Lymphocytes No effect		NoneNo effect	1 study	34 people
Early Virologic Response	Improves (the measure goes up)			17 people
Liver Enzymes	Changes; see studies			17 people

Conjugated Linoleic Acid

C-Reactive Protein (CRP)
Inflammation: improves
Interleukin 2: improves

Conjugated Linoleic Acid: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
C-Reactive Protein (CRP) No effect		NoneNo effect	1 study	63 people
Inflammation	Improves (the measure goes down)		1 study	61 people
Interleukin 2	Improves (the measure goes up)		1 study	10 people
Cell Adhesion Factors	Improves (the measure goes down)			53 people
Crohn's Disease Symptoms	Improves (the measure goes down)			10 people
Interleukin 6	Improves (the measure goes down)			10 people
TNF-Alpha	Improves (the measure goes down)			63 people

Docosahexaenoic Acid

B Cell Count
Inflammation: improves
Natural Killer Cell Activity: improves

Docosahexaenoic Acid: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
B Cell Count No effect		NoneNo effect	1 study	58 people
Inflammation	Improves (the measure goes down)			12 people
Natural Killer Cell Activity	Improves (the measure goes up)			58 people
Natural Killer Cell Content	Improves (the measure goes up)			46 people
Oxidative Stress Biomarkers	Improves (the measure goes down)			46 people
T Cell Count	Improves (the measure goes up)			58 people
TNF-Alpha	Improves (the measure goes down)			12 people

Hesperidin

B Cell Count
C-Reactive Protein (CRP): improves
Neutrophil Count: improves

Hesperidin: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
B Cell Count No effect		NoneNo effect		24 people
C-Reactive Protein (CRP)	Improves (the measure goes down)		1 study	296 people
Neutrophil Count	Improves (the measure goes up)		1 study	24 people
Intercellular Adhesion Molecule 1	Changes; see studies			296 people
Interleukin 6	Improves (the measure goes down)			296 people
Natural Killer Cell Activity	Improves (the measure goes up)			24 people
Natural Killer Cell Content	Improves (the measure goes up)			24 people
Neutrophil Activity	Improves (the measure goes up)			24 people
sE-Selectin	Improves (the measure goes up)			296 people
T Cell Count	Improves (the measure goes up)			24 people
Vascular Adhesion Protein-1	Improves (the measure goes up)			296 people
White Blood Cell Count	Improves (the measure goes up)			24 people

Quercetin

Interleukin 6
Intestinal Permeability: improves
Uric Acid: improves

Quercetin: outcomes studied for Immune Health
Outcome	Effect	Size	People
Interleukin 6 No effect		NoneNo effect	15 people
Intestinal Permeability	Improves (the measure goes up)		8 people
Uric Acid	Improves (the measure goes down)		15 people

Tongkat Ali

B Cell Count
Neutrophil Count: improves
CD4 Lymphocytes: improves

Tongkat Ali: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
B Cell Count No effect		NoneNo effect		84 people
Neutrophil Count	Improves (the measure goes up)		1 study	84 people
CD4 Lymphocytes	Improves (the measure goes up)			84 people
CD8 Lymphocytes	Improves (the measure goes up)			84 people
Lymphocyte Count	Improves (the measure goes up)			84 people
Mood	Improves (the measure goes up)			84 people
Natural Killer Cell Content	Improves (the measure goes up)			84 people
T Cell Count	Improves (the measure goes up)			84 people

Tetradecyl Thioacetic Acid

Blood glucose
HbA1c: improves
Heart Rate: improves

Tetradecyl Thioacetic Acid: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
Blood glucose No effect		NoneNo effect		18 people
HbA1c	Improves (the measure goes down)		1 study	10 people
Heart Rate	Improves (the measure goes down)		1 study	18 people
C-Reactive Protein (CRP)	Improves (the measure goes down)			18 people
Glycemic Control	Improves (the measure goes up)			10 people
High-density lipoprotein (HDL)	Improves (the measure goes up)			28 people
HIV Viral Load	Improves (the measure goes up)			10 people
Liver Enzymes	Changes; see studies			28 people
Low-density lipoprotein (LDL)	Improves (the measure goes down)			28 people
Red Blood Cell Count	Improves (the measure goes up)			18 people
Serum T4	Improves (the measure goes up)			18 people
Thyroid-Stimulating Hormone	Improves (the measure goes up)			18 people
TNF-Alpha	Improves (the measure goes down)			10 people
Triglycerides	Improves (the measure goes down)			28 people
Uric Acid	Improves (the measure goes down)			18 people
White Blood Cell Count	Improves (the measure goes up)			18 people

Vitamin E

B Cell Count
Oxidative Stress Biomarkers: improves
Interferon Gamma: improves

Vitamin E: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
B Cell Count No effect		NoneNo effect		53 people
Oxidative Stress Biomarkers	Improves (the measure goes down)		3 studies	32 people
Interferon Gamma	Improves (the measure goes up)		2 studies	322 people
CD8 Lymphocytes	Improves (the measure goes up)		1 study	53 people
Creatinine	Improves (the measure goes up)		1 study	32 people
Immunoglobulin G	Improves (the measure goes up)		1 study	140 people
Liver Enzymes	Changes; see studies		1 study	32 people
White Blood Cell Count	Improves (the measure goes up)		1 study	120 people
CD4 Lymphocytes	Improves (the measure goes up)			53 people
Immunity	Improves (the measure goes up)			281 people
Immunoglobulin A	Improves (the measure goes up)			32 people
Immunoglobulin M	Improves (the measure goes up)			32 people
Interleukin 2	Improves (the measure goes up)			193 people
Interleukin 4	Improves (the measure goes up)			322 people
Natural Killer Cell Content	Improves (the measure goes up)			53 people
Prostaglandin E2	Improves (the measure goes down)			32 people
Red Blood Cell Count	Improves (the measure goes up)			32 people
Vaccine Augmentation	Improves (the measure goes up)			196 people

Chlorella

Body Fat
Immunity: improves
Vaccine Augmentation: improves

Chlorella: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
Body Fat No effect		NoneNo effect		15 people
Immunity	Improves (the measure goes up)		1 study	15 people
Vaccine Augmentation	Improves (the measure goes up)		1 study	117 people

Citrulline

DNA Damage
Immunity: improves
Liver Enzymes: changes; see studies

Citrulline: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
DNA Damage No effect		NoneNo effect		17 people
Immunity	Improves (the measure goes up)		1 study	17 people
Liver Enzymes	Changes; see studies			17 people
Oxidative Stress Biomarkers	Improves (the measure goes down)			17 people

Colostrum

B Cell Count
C-Reactive Protein (CRP)
Upper Respiratory Tract Infection Symptoms: improves

Colostrum: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
B Cell Count No effect		NoneNo effect		138 people
C-Reactive Protein (CRP) No effect		NoneNo effect		52 people
Upper Respiratory Tract Infection Symptoms	Improves (the measure goes down)		4 studies	78 people
Diarrhea Symptoms	Improves (the measure goes down)		3 studies	20 people
IGF-1	Improves (the measure goes up)		2 studies	39 people
Intestinal Parasites	Improves (the measure goes up)		2 studies	20 people
CD4 Lymphocytes	Improves (the measure goes up)		1 study	138 people
Exercise-Induced Immune Suppression	Improves (the measure goes up)		1 study	9 people
Immunity	Improves (the measure goes up)		1 study	138 people
Immunoglobulin A	Improves (the measure goes up)		1 study	135 people
Immunoglobulin M	Improves (the measure goes up)		1 study	70 people
Natural Killer Cell Content	Improves (the measure goes up)		1 study	150 people
Neutrophil Count	Improves (the measure goes up)		1 study	9 people
Testosterone	Improves (the measure goes up)		1 study	9 people
CD8 Lymphocytes	Improves (the measure goes up)			138 people
Cortisol	Improves (the measure goes down)			18 people
Fat Oxidation	Improves (the measure goes up)			9 people
Growth Hormone	Improves (the measure goes up)			9 people
Immunoglobulin E	Improves (the measure goes up)			9 people
Immunoglobulin G	Improves (the measure goes up)			100 people
Interferon Gamma	Improves (the measure goes up)			9 people
Interleukin 1-alpha	Improves (the measure goes up)			9 people
Interleukin 10	Improves (the measure goes up)			9 people
Interleukin 6	Improves (the measure goes down)			9 people
Interleukin 8	Changes; see studies			9 people
Lymphocyte Count	Improves (the measure goes up)			9 people
Macrophage Activity	Improves (the measure goes up)			12 people
T Cell Count	Improves (the measure goes up)			138 people
TNF-Alpha	Improves (the measure goes down)			9 people
Upper Respiratory Tract Infection Risk	Changes; see studies			78 people
Vaccine Augmentation	Improves (the measure goes up)			156 people
White Blood Cell Count	Improves (the measure goes up)			12 people

Alpha-Linolenic Acid (ALA)

B Cell Count
Oxidative Stress Biomarkers: changes; see studies
Natural Killer Cell Activity: improves

Alpha-Linolenic Acid (ALA): outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
B Cell Count No effect on B cell count		NoneNo effect		46 people
Oxidative Stress Biomarkers	Changes; see studies		1 study	46 people
Natural Killer Cell Activity	Improves (the measure goes up)			46 people
Natural Killer Cell Content	Improves (the measure goes up)			46 people
T Cell Count	Improves (the measure goes up)			46 people

Panax Ginseng (Korean Ginseng)

Adiponectin
Immunoglobulin A: improves
Fatigue Symptoms: improves

Panax Ginseng (Korean Ginseng): outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
Adiponectin No effect		NoneNo effect		80 people
Immunoglobulin A	Improves (the measure goes up)		1 study	38 people
Fatigue Symptoms	Improves (the measure goes down)			80 people
Liver Enzymes	Changes; see studies			80 people
Peak power output (PPO)	Improves (the measure goes up)			38 people

Cocoa Extract

Adrenocorticotropic Hormone
Fat Oxidation: improves
Cortisol: improves

Cocoa Extract: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
Adrenocorticotropic Hormone No effect		NoneNo effect		14 people
Fat Oxidation	Improves (the measure goes up)		1 study	14 people
Cortisol	Improves (the measure goes down)			14 people
Exercise-Induced Oxidation	Changes; see studies			14 people
Heart Rate	Improves (the measure goes down)			14 people
Insulin	Changes; see studies			14 people
Interleukin 6	Improves (the measure goes down)			14 people
Neutrophil Activity	Improves (the measure goes up)			14 people
Neutrophil Count	Improves (the measure goes up)			14 people

Creatine

Anti-Oxidant Enzyme Profile
Muscle Damage: changes; see studies
Creatinine: improves

Creatine: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
Anti-Oxidant Enzyme Profile No effect		NoneNo effect		25 people
Muscle Damage	Changes; see studies		4 studies	50 people
Creatinine	Improves (the measure goes up)		3 studies	25 people
Oxidative Stress Biomarkers	Improves (the measure goes down)		1 study	25 people
C-Reactive Protein (CRP)	Improves (the measure goes down)			25 people
Fatigue Symptoms	Improves (the measure goes down)			25 people
TNF-Alpha	Improves (the measure goes down)			25 people

Lactobacillus reuteri

B Cell Count
Immunity: improves
Immunoglobulin A: improves

Lactobacillus reuteri: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
B Cell Count No effect		NoneNo effect		31 people
Immunity	Improves (the measure goes up)		1 study	31 people
Immunoglobulin A	Improves (the measure goes up)		1 study	23 people
Lymphocyte Count	Improves (the measure goes up)			31 people
Monocyte Count	Improves (the measure goes up)			31 people

Alpha-Lipoic Acid

Oxidative Stress Biomarkers: changes; see studies

Alpha-Lipoic Acid: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Oxidative Stress Biomarkers	Changes; see studies		4 studies	33 people

Coenzyme Q10

Inflammation: improves

Coenzyme Q10: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Inflammation	Improves (the measure goes down)		2 studies	20 people

Glutamine

Insulin: changes; see studies
Immunity: improves
Blood glucose: worsens

Glutamine: outcomes studied for Immune Health
Outcome	Effect	Size	Studies	People
Insulin	Changes; see studies		2 studies	33 people
Immunity	Improves (the measure goes up)		1 study	69 people
Blood glucose Small Detriment	Worsens (the measure goes up)	Small effect		33 people
C-Reactive Protein (CRP)	Improves (the measure goes down)			33 people
Cortisol	Improves (the measure goes down)			33 people
Inflammation	Improves (the measure goes down)			33 people
Testosterone	Improves (the measure goes up)			33 people

DHEA

Muscle Mass: improves

DHEA: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Muscle Mass	Improves (the measure goes up)		2 studies	40 people

Zinc

Upper Respiratory Tract Infection Risk: changes; see studies

Zinc: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Upper Respiratory Tract Infection Risk	Changes; see studies		1 study	100 people

Feverfew

Erythema: improves

Feverfew: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Erythema	Improves (the measure goes up)		1 study	8 people

Pomegranate seed oil

TNF-Alpha: improves

Pomegranate seed oil: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	TNF-Alpha	Improves (the measure goes down)		1 study	45 people

Astragalus

Immunity: improves

Astragalus: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Immunity	Improves (the measure goes up)		1 study	16 people

Phlebodium aureum

Upper Respiratory Tract Infection Risk: changes; see studies

Phlebodium aureum: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Upper Respiratory Tract Infection Risk	Changes; see studies			116 people

Prescription medicines and peptides studied, for context

These are not supplements. Most need a prescription, and some are research compounds with no approved use. They are listed so the supplement evidence above can be read against them.

1 medicine or peptide

KPV

Pro-inflammatory Cytokine Reduction: changes; see studies
Macrophage Activation Suppression: changes; see studies

KPV: outcomes studied for Immune Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Pro-inflammatory Cytokine Reduction Inhibition of TNF-α, IL-1β, and IL-6 secretion at nanomolar concentrations	Changes; see studies	Moderate effect	70 studies	90 people
	Macrophage Activation Suppression Inhibition of LPS-induced cytokine synthesis and CD86 expression	Changes; see studies	Moderate effect	69 studies	60 people

What the published studies found

12 automated readings

Automated reading of the published studies (Decosa evidence engine), for outcomes Dr. Grey has not graded yet. It is not a Dr. Grey grade and does not change one. How it is read

Citrulline: respiratory infections
Too few usable studies were found to tell whether Citrulline changes respiratory infections. 8 studies were read and none could be counted.
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Elderberry: influenza
The best available review (2019, 180 people) found an improvement in influenza. 3 of the 4 studies read agree; 1 found no clear difference. The evidence is limited.
4 studies counted of 9 read: 1 review and 3 trials (147 people in the trials).
1. Meta-analysis, 2019; 180 people: improves (the review the verdict rests on). Supplementation with elderberry was found to substantially reduce upper respiratory symptoms. The quantitative synthesis of … Black elderberry (Sambucus nigra) supplementation effectively treats upper respiratory symptoms: A meta-analysis of randomized, controlled clinical trialsPubMed 30670267
2. Randomised trial, 2020; 87 people; emergency room patients with influenza: no clear difference. no evidence that elderberry benefits the duration Elderberry Extract Outpatient Influenza Treatment for Emergency Room Patients Ages 5 and Above: a Randomized, Double-Blind, Placebo-Controlled TrialPubMed 32929634
3. Randomised trial, 2004; 60 people; patients with influenza-like symptoms: improves. Symptoms were relieved on average 4 days earlier Randomized study of the efficacy and safety of oral elderberry extract in the treatment of influenza A and B virus infectionsPubMed 15080016
4. Randomised trial, 1995; individuals in agricultural community during outbreak: improves. Inhibition of several strains of influenza virus in vitro and reduction of symptoms by an elderberry extract (Sambucus nigra L.) during an outbreak of influenza B PanamaPubMed 9395631
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Fish Oil: respiratory infections
The best available review (2018) found little or no difference in respiratory infections. All 2 studies read agree. The evidence is limited.
2 studies counted of 10 read: 2 reviews.
1. Meta-analysis, 2018: no clear difference (the review the verdict rests on). did not reveal any differences, neither in infections rates Intravenous fish oil in critically ill and surgical patients - Historical remarks and critical appraisalPubMed 28747247
2. Meta-analysis, 2014; 6 studies, 390 people: no clear difference. no effect on infections (RR, 0.76 Parenteral fish oil lipid emulsions in the critically ill: a systematic review and meta-analysisPubMed 23609773
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Multivitamin: respiratory infections
The studies disagree. The best available review (2006, 20 studies) did not settle it for respiratory infections, while 1 of the 2 studies read found no clear answer. The evidence is very weak.
Side effects: 1 of the 3 studies that reported on them found more with Multivitamin (non-serious adverse events).
2 studies counted of 10 read: 2 reviews.
1. Meta-analysis, 2006; 20 studies: mixed results (the review the verdict rests on). significantly less episodes of infection in those supplemented A systematic review of multivitamin and multimineral supplementation for infectionPubMed 16756533
2. Meta-analysis, 2005; 8 studies; elderly people: unclear: evidence too weak to tell. Role of multivitamins and mineral supplements in preventing infections in elderly people: systematic review and meta-analysis of randomised controlled trialsPubMed 15805125
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Panax Ginseng (Korean Ginseng): respiratory infections
The best available review (2021, 39 studies, 16,797 people) found an improvement in respiratory infections. 3 of the 7 studies read agree; 2 found no clear answer, 2 found no clear difference. The evidence is moderate.
7 studies counted of 11 read: 3 reviews and 4 trials (1,582 people in the trials).
1. Systematic review, 2021; 39 studies, 16,797 people: improves (the review the verdict rests on). Effects of select dietary supplements on the prevention and treatment of viral respiratory tract infections: a systematic review of randomized controlled trialsPubMed 33858268
2. Meta-analysis, 2020; 10 studies; healthy adults: unclear: evidence too weak to tell. significant effect on SAURIs incidence (RR = 0.69 Ginseng integrative supplementation for seasonal acute upper respiratory infections: A systematic review and meta-analysisPubMed 32951718
3. Systematic review, 2011; 5 studies, 747 people; healthy adults: unclear: evidence too weak to tell. tendency toward a lower incidence of having at least one common cold North American (Panax quinquefolius) and Asian Ginseng (Panax ginseng) Preparations for Prevention of the Common Cold in Healthy Adults: A Systematic ReviewPubMed 19592479
4. Randomised trial, 2012; 293 people; patients with early-stage, untreated chronic lymphocytic leukemia: no clear difference. no significant differences of the 2 a priori primary end points A randomized, controlled trial of Panax quinquefolius extract (CVT-E002) to reduce respiratory infection in patients with chronic lymphocytic leukemiaPubMed 22266154
5. Randomised trial, 2011; 783 people; influenza-vaccinated community-dwelling adults: no clear difference. incidence of LCCUs in the ITT group was 5.5%, 5.2%, and 4.6% Efficacy and Safety of CVT-E002, a Proprietary Extract of Panax quinquefolius in the Prevention of Respiratory Infections in Influenza-Vaccinated Community-Dwelling Adults: A Multicenter, Randomized, Double-Blind, and Placebo-Controlled TrialPubMed 23074661
6. Randomised trial, 2005; 279 people; adults with history of at least 2 colds: improves. mean number of colds per person was lower Efficacy of an extract of North American ginseng containing poly-furanosyl-pyranosyl-saccharides for preventing upper respiratory tract infections: a randomized controlled trialPubMed 16247099
7. Randomised trial, 1996; 227 people; 227 volunteers visiting private practices in Milan: improves. frequency of influenza or common cold between weeks 4 and 12 was 42 cases in … Efficacy and safety of the standardised Ginseng extract G115 for potentiating vaccination against the influenza syndrome and protection against the common cold [corrected]PubMed 8879982
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Probiotics: respiratory infections
A Cochrane review (2022, 24 studies, 6,950 people) found a small improvement in respiratory infections. That review studied people of all ages at risk of acute URTIs. 6 of the 7 studies read agree; 1 found no clear answer. The evidence is limited.
7 studies counted of 10 read: 6 reviews and 1 trial (120 people in the trials).
1. Systematic review, 2022; 24 studies, 6,950 people; people of all ages at risk of acute URTIs: improves (the review the verdict rests on). probiotics may reduce the number of participants diagnosed with URTIs Probiotics for preventing acute upper respiratory tract infectionsPubMed 36001877
2. Systematic review, 2026; 8 studies, 1,158 people; children with respiratory tract infections: improves. Comparative efficacy and safety of probiotic for respiratory tract infections in children: a network meta-analysisPubMed 42602161
3. Meta-analysis, 2026; 32 studies; patients with upper respiratory tract infections: unclear: evidence too weak to tell. pooled incidence reduction was non-significant (RD = -0.07 The Efficacy of Probiotics in Treating Upper Respiratory Tract Infections, Allergic Rhinitis, and Chronic Rhinosinusitis: A Systematic Review and Meta-AnalysisPubMed 42197372
4. Meta-analysis, 2025; 13 studies; patients with respiratory diseases: improves. significantly reduced the incidence of respiratory disease episodes Role of Lacticaseibacillus rhamnosus GG in the Management of Respiratory Diseases: A Systematic Review and Meta-AnalysisPubMed 40612762
5. Meta-analysis, 2019; 17 studies, 3,488 people; children aged up to 18 years: improves. Probiotics for preventing acute otitis media in childrenPubMed 31210358
6. Meta-analysis, 2014; 8 studies, 1,083 people; ICU patients receiving mechanical ventilation: improves. use of probiotics decreased the incidence of VAP Probiotics for preventing ventilator-associated pneumoniaPubMed 25344083
7. Randomised trial, 2026; 120 people; children with recurrent respiratory tract infections: improves. Probiotics significantly improved clinical efficacy compared with placebo Probiotic modulation of gut microbiota with Bifidobacterium animalis subsp. lactis XLTG11 and Lactobacillus plantarum CCFM8661 mitigates recurrent respiratory infections in children: a randomised-controlled trialPubMed 42090020
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Saffron: respiratory infections
Too few usable studies were found to tell whether Saffron changes respiratory infections. 4 studies were read and none could be counted.
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Selenium: respiratory infections
The studies read are too weak to tell whether Selenium changes respiratory infections. The strongest review read studied critically ill adults. The evidence is very weak.
6 studies counted of 11 read: 4 reviews and 2 trials (159 people in the trials).
1. Meta-analysis, 2015; 16 studies, 2,084 people; critically ill adults: unclear: evidence too weak to tell (the review the verdict rests on). Selenium supplementation for critically ill adultsPubMed 26214143
2. Systematic review, 2020; 43 studies; humans with viral and respiratory infections: improves. selenium and zinc have also shown favourable immune-modulatory effects Enhancing immunity in viral infections, with special emphasis on COVID-19: A reviewPubMed 32334392
3. Meta-analysis, 2019; 13 studies; patients with sepsis syndrome: no clear difference. incidence of renal failure, secondary infection or duration A meta-analysis of randomized controlled trials: Efficacy of selenium treatment for sepsisPubMed 30817625
4. Meta-analysis, 2016; 21 studies: no clear difference. no significant treatment effect of parenteral Se High-dose intravenous selenium does not improve clinical outcomes in the critically ill: a systematic review and meta-analysisPubMed 27788688
5. Randomised trial, 2025; 60 people; hospitalised under-five children with acute lower respiratory tract infections: improves. reduces the need for mechanical ventilation Oral Selenium as an Adjunct in the Treatment of Acute Lower Respiratory Tract Infections in Children: A Double-Blind Randomized Controlled TrialPubMed 40202578
6. Randomised trial, 2018; 99 people: no clear difference. The incidence of VAP was 19.4/1000days of mechanical ventilation in the placebo group while it … Antioxidant reserve of the lungs and ventilator-associated pneumonia: A clinical trial of high dose selenium in critically ill patientsPubMed 29288963
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Vitamin C: respiratory infections
A Cochrane review (2013, 29 studies, 11,306 people) found little or no difference in respiratory infections. 1 of the 3 studies read agree; 1 found an improvement, 1 found no clear answer. The evidence is moderate.
3 studies counted of 6 read: 3 reviews.
1. Meta-analysis, 2013; 29 studies, 11,306 people: no clear difference (the review the verdict rests on). pooled RR was 0.97 (95% confidence interval (CI) 0.94 to 1.00) Vitamin C for preventing and treating the common coldPubMed 23440782
2. Meta-analysis, 2022; 10 studies: improves. shorter duration of respiratory infection (SMD -0.36 Effect of Vitamin C Supplements on Respiratory Tract Infections: A Systematic Review and Meta-AnalysisPubMed 34967304
3. Meta-analysis, 2013; 6 studies, 2,532 people: unclear: evidence too weak to tell. statistically significant (80% or greater) reduction in pneumonia incidence Vitamin C for preventing and treating pneumoniaPubMed 23925826
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Vitamin D: respiratory infections
A Cochrane review (2026, 107 studies, 31,521 people) found a small improvement in respiratory infections. That review studied children up to five years of age. 5 of the 8 studies read agree; 2 found no clear difference, 1 found no clear answer. The evidence is limited.
8 studies counted of 10 read: 5 reviews and 3 trials (540 people in the trials).
1. Meta-analysis, 2026; 107 studies, 31,521 people; children up to five years of age: improves (the review the verdict rests on). slight reduction in the proportion of children who make ARI-related healthcare visits Vitamin D for preventing acute respiratory infections in children up to five years of agePubMed 42037591
2. Meta-analysis, 2025; 40 studies, 61,589 people: no clear difference. did not statistically significantly affect overall ARI risk Vitamin D supplementation to prevent acute respiratory infections: systematic review and meta-analysis of stratified aggregate dataPubMed 39993397
3. Meta-analysis, 2025; 37 studies, 16,000 people: unclear: evidence too weak to tell. SOR was 0.92 (0.86-0.99) for all trials Vitamin D, acute respiratory infections, and Covid-19: The curse of small-size randomised trials. A critical review with meta-analysis of randomised trialsPubMed 39808630
4. Systematic review, 2025; 38 studies; offspring of mothers given vitamin D in pregnancy: improves. vitamin D supplementation reduced respiratory tract infections Effects of Maternal Vitamin D Supplementation on Childhood HealthPubMed 41129483
5. Meta-analysis, 2016; 4 studies, 3,198 people; children under five years of age: no clear difference. episodes of 'radiologically confirmed' first or only episode of pneumonia were little different Vitamin D supplementation for preventing infections in children under five years of agePubMed 27826955
6. Randomised trial, 2026; 80 people; ICU patients with traumatic lung contusion, VAP, sepsis: improves. faster recovery from lung contusion, VAP, and sepsis Effect of vitamin D as Nutrition Supplement on Patients with Prolonged Ventilation due to Ventilator Associated Pneumonia and Sepsis Followed Severe Traumatic Lung Contusion: A Randomized Controlled TrialPubMed 41525115
7. Randomised trial, 2025; 200 people; healthy 6-8-year-old children: improves. had 17% fewer sick days due to ARTI Effects of vitamin D supplementation on acute respiratory tract infections in 6-8-year-old children: a randomized clinical trialPubMed 40310565
8. Randomised trial, 2015; 260 people; pregnant women and their infants: improves. proportion of children making any ARI visits was smaller in the higher-dose Reduced primary care respiratory infection visits following pregnancy and infancy vitamin D supplementation: a randomised controlled trialPubMed 25283480
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Vitamin E: respiratory infections
The 2 studies read (29,633 people in all) mostly found little or no difference in respiratory infections. The evidence is limited.
2 studies counted of 10 read: 2 trials (29,633 people in the trials).
1. Randomised trial, 2010; 500 people; elderly nursing home residents: unclear: evidence too weak to tell. effect of vitamin E on lower RI depended on sex IL-2 and IL-10 gene polymorphisms are associated with respiratory tract infection and may modulate the effect of vitamin E on lower respiratory tract infections in elderly nursing home residentsPubMed 20484443
2. Randomised trial, 2004; 29,133 people; male smokers aged 50 to 69 years: no clear difference. Vitamin E and beta-carotene supplementation and hospital-treated pneumonia incidence in male smokersPubMed 14769738
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.
Zinc: respiratory infections
A Cochrane review (2024, 34 studies, 8,526 people) found little or no difference in respiratory infections. That review studied children and adults with or at risk of common cold. 3 of the 6 studies read agree; 3 found an improvement. The evidence is limited.
Side effects: 2 of the 5 studies that reported on them found more with Zinc (bad taste, nausea, non-serious adverse events).
6 studies counted of 8 read: 6 reviews.
1. Systematic review, 2024; 34 studies, 8,526 people; children and adults with or at risk of common cold: no clear difference (the review the verdict rests on). little or no reduction in the risk of developing a cold Zinc for prevention and treatment of the common coldPubMed 38719213
2. Systematic review, 2026; 19 studies, 11,576 people; children under 18 years old: no clear difference. Direct comparison meta-analysis showed no statistically significant differences between low-dose vitamin D, vitamin A, vitamin … Comparative efficacy of nutritional supplements for the prevention of respiratory tract infections in children: a systematic review and network meta-analysisPubMed 42143317
3. Systematic review, 2026; children with respiratory infections: improves. reducing the incidence and burden of respiratory infections The Role of Zinc in Pediatric Respiratory Infections: Evidence from Clinical Trials and Real-World StudiesPubMed 41754074
4. Meta-analysis, 2022; 14 studies, 9,940 people; preterm or low birth weight infants: no clear difference. no effect on acute respiratory infections Enteral Zinc Supplementation in Preterm or Low Birth Weight Infants: A Systematic Review and Meta-analysisPubMed 35921675
5. Meta-analysis, 2016; 6 studies, 5,193 people; children aged 2 months to 59 months: improves. Zinc supplementation for the prevention of pneumonia in children aged 2 months to 59 monthsPubMed 27915460
6. Meta-analysis, 2013; 18 studies, 1,781 people; healthy people with common cold symptoms: improves. The incidence rate ratio (IRR) of developing a cold (IRR 0.64, 95% CI 0.47 to … Zinc for the common coldPubMed 23775705
Automated reading of the published studies (Decosa evidence engine), run 30 Sep 2026. It reads abstracts, can miss studies, and a repeat run can differ.

Key findings

C-Reactive Protein (CRP)BoronImproves (the measure goes down)
CD4+ CountAndrographisImproves (the measure goes up)
Antioxidant StatusTriphala (Emblica officinalis, Terminalia chebula, Terminalia bellirica)Improves (the measure goes up)

The Immune Health & Function protocol

2 primary supplements · 2 supporting supplements

Vitamin D2,000–4,000 IU daily (target 40–60 ng/mL)
Zinc15–30 mg daily

See the full protocol

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Studies cited

7 studies from PubMed

Double-blinded randomized controlled trial for immunomodulatory effects of Tulsi (Ocimum sanctum Linn.) leaf extract on healthy volunteersJ Ethnopharmacol · PMID 21619917
Aged garlic extract prevents a decline of NK cell number and activity in patients with advanced cancerJ Nutr · PMID 16484572
Systemic production of IFN-alpha by garlic (Allium sativum) in humansJ Interferon Cytokine Res · PMID 17523869
Effect of plant-based diets on obesity-related inflammatory profiles: a systematic review and meta-analysis of intervention trialsObes Rev · PMID 27405372
Effects of Dietary Patterns on Biomarkers of Inflammation and Immune Responses: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.Adv Nutr · PMID 34607347
The influence of resistance training on inflammatory markers, body composition and functional capacity in healthy older adults: A systematic review and meta-analysis.Arch Gerontol Geriatr · PMID 39740358
Regular consumption of concord grape juice benefits human immunityJ Med Food · PMID 21138361