Skip to content
Dr. Grey AI

Condition

Optimal Nutrient Levels

Optimal nutrient levels means having enough of the vitamins and minerals your body relies on for bones, nerves and immunity, which diet, age or little sun can make harder. The evidence is strongest for vitamin D, omega-3s and magnesium, and a global review called vitamin D shortfalls a widespread problem. Separately, piperine from black pepper increased how much curcumin people absorbed, though that came from only about 60 people.

Sources: PMID 28768407

Supplements studied
2
Graded outcomes
1
Trials
1
People studied
28

Evidence by supplement

  • Strong
  • Moderate
  • Limited
  • Very limited

2 supplements

Black Pepper: outcomes studied for Optimal Nutrient Levels
GradeOutcomeEffectSizeStudiesPeopleStudies list
Curcumin Bioavailability

20mg piperine increased curcumin bioavailability by 2000% in humans (PMID: 9619120); consistent enhancement across multiple studies

Improves (the measure goes up)Large effect60 people
Zinc: outcomes studied for Optimal Nutrient Levels
GradeOutcomeEffectSizeStudiesPeopleStudies list
Iron AbsorptionImproves (the measure goes up)4 studies28 people

Studies that measured iron absorption

and 1 more on the Zinc page

Key findings

  • Curcumin BioavailabilityBlack PepperImproves (the measure goes up)

The Optimal Nutrient Levels for Health protocol

2 primary supplements · 7 supporting supplements

  • Vitamin D2,000–4,000 IU daily (adjust based on blood levels; target 40–60 ng/mL)
  • Omega-3 Fatty Acids1–2 g EPA+DHA daily (higher for specific conditions)

See the full protocol

Shop the evidence-backed picks

The supplement graded A or B for Optimal Nutrient Levels. Each opens third-party tested products for that supplement.

  • Grade B

Links to Fullscript, iHerb or Thorne carry our referral, so we may earn a commission at no extra cost to you. Grades come from the research and never change based on what we earn. Fullscript asks for a free account before it shows its catalog and prices. Full disclosure

Studies cited

86 studies from PubMed

  1. Piperine, an alkaloid of black pepper seeds, anti-cancer activities and pharmacokineticsNutr Cancer, 2013 · PMID 23768180
  2. Anti-inflammatory effects of piperine in lipopolysaccharide-stimulated BV2 microglial cellsInt Immunopharmacol, 2012 · PMID 17987447
  3. Effects of piperine on the pharmacokinetics of resveratrol in healthy volunteersMol Nutr Food Res, 2011 · PMID 30347592
  4. Piperine inhibits the activities of cytochrome P450 2C9, 2C19 and 3A4 in vitroDrug Metab Dispos, 2010 · PMID 20480025
  5. Black pepper and health claims: a comprehensive treatiseCrit Rev Food Sci Nutr, 2007 · PMID 22531131
  6. Piperine, a major principle of black pepper, inhibits human P-glycoprotein and CYP3A4J Pharmacol Exp Ther, 2002 · PMID 22664528
  7. Influence of piperine on the pharmacokinetics of curcumin in animals and human volunteersPlanta Med, 1998 · PMID 9619120
  8. Effects of folic acid and folic acid plus zinc supplements on the sperm characteristics and pregnancy outcomes of infertile men: A systematic review and meta-analysis.Heliyon · PMID 37539255
  9. A systematic review and meta-analysis examining the role of zinc supplementation in ameliorating physical and psychological manifestations of premenstrual syndrome in young females.Eur J Obstet Gynecol Reprod Biol · PMID 40435711
  10. Effect of Zinc Supplementation on Physical and Psychological Symptoms, Biomarkers of Inflammation, Oxidative Stress, and Brain-Derived Neurotrophic Factor in Young Women with Premenstrual Syndrome: a Randomized, Double-Blind, Placebo-Controlled TrialBiol Trace Elem Res · PMID 31154571
  11. Effect of zinc sulfate supplementation on premenstrual syndrome and health-related quality of life: Clinical randomized controlled trialJ Obstet Gynaecol Res · PMID 28188965
  12. Effect of zinc supplementation on markers of insulin resistance, oxidative stress, and inflammation among prepubescent children with metabolic syndromeMetab Syndr Relat Disord · PMID 21028969
  13. Effect of zinc supplementation on insulin resistance and components of the metabolic syndrome in prepubertal obese childrenHormones · PMID 20045801
  14. Effect of zinc supplementation on antioxidant activity in young wrestlersBiol Trace Elem Res · PMID 19597720
  15. Randomized, double-blind trial of 220 mg zinc sulfate twice daily in the treatment of rosaceaInt J Dermatol · PMID 22435439
  16. Oral zinc sulfate in the treatment of rosacea: a double-blind, placebo-controlled studyInt J Dermatol · PMID 16863527
  17. Prophylaxis and treatment of rhinovirus colds with zinc gluconate lozengesJ Antimicrob Chemother · PMID 3440773
  18. Two randomized controlled trials of zinc gluconate lozenge therapy of experimentally induced rhinovirus coldsAntimicrob Agents Chemother · PMID 2820298
  19. Zinc gluconate and the common cold: a controlled clinical studyJ Int Med Res · PMID 1397668
  20. Duration and severity of symptoms and levels of plasma interleukin-1 receptor antagonist, soluble tumor necrosis factor receptor, and adhesion molecules in patients with common cold treated with zinc acetateJ Infect Dis · PMID 18279051
  21. Zinc acetate lozenges for the treatment of the common cold: a randomised controlled trialBMJ Open · PMID 31980506
  22. Zinc gluconate lozenges for treating the common cold. A randomized, double-blind, placebo-controlled studyAnn Intern Med · PMID 8678384
  23. Effect of treatment with zinc gluconate or zinc acetate on experimental and natural coldsClin Infect Dis · PMID 11073753
  24. Reduction in duration of common colds by zinc gluconate lozenges in a double-blind studyAntimicrob Agents Chemother · PMID 6367635
  25. Zinc gluconate lozenges for common cold. A double-blind clinical trialDan Med Bull · PMID 2192839
  26. Duration of symptoms and plasma cytokine levels in patients with the common cold treated with zinc acetate. A randomized, double-blind, placebo-controlled trialAnn Intern Med · PMID 10929163
  27. Zinc supplementation decreases incidence of infections in the elderly: effect of zinc on generation of cytokines and oxidative stressAm J Clin Nutr · PMID 17344507
  28. Zinc sulfate in the prevention of radiation-induced oropharyngeal mucositis: a prospective, placebo-controlled, randomized studyInt J Radiat Oncol Biol Phys · PMID 14697435
  29. Zinc increases the effects of essential amino acids-whey protein supplements in frail elderlyJ Nutr Health Aging · PMID 19536417
  30. Effects of zinc supplementation on efficacy of antidepressant therapy, inflammatory cytokines, and brain-derived neurotrophic factor in patients with major depressionNutr Neurosci · PMID 23602205
  31. Zinc monotherapy increases serum brain-derived neurotrophic factor (BDNF) levels and decreases depressive symptoms in overweight or obese subjects: A double-blind, randomized, placebo-controlled trialNutr Neurosci · PMID 24621065
  32. Zinc supplementation combined with antidepressant drugs for treatment of patients with depression: a systematic review and meta-analysisNutr Rev · PMID 32885249
  33. Effect of zinc supplementation on mood states in young women: a pilot studyEur J Clin Nutr · PMID 20087376
  34. Zinc supplementation augments efficacy of imipramine in treatment resistant patients: a double blind, placebo-controlled studyJ Affect Disord · PMID 19278731
  35. Zinc supplementation improved cognitive performance and taste acuity in Indian adolescent girlsJ Am Coll Nutr · PMID 20368377
  36. Short-term zinc supplementation in women with non-insulin-dependent diabetes mellitus: effects on plasma 5'-nucleotidase activities, insulin-like growth factor I concentrations, and lipoprotein oxidation rates in vitroAm J Clin Nutr · PMID 9280186
  37. Effect of zinc supplementation in the management of type 2 diabetes: A grading of recommendations assessment, development, and evaluation-assessed, dose-response meta-analysis of randomized controlled trials.Crit Rev Food Sci Nutr · PMID 37183697
  38. Effect of zinc supplementation on glycemic biomarkers: an umbrella of interventional meta-analyses.Diabetol Metab Syndr · PMID 38849958
  39. Zinc decreases C-reactive protein, lipid peroxidation, and inflammatory cytokines in elderly subjects: a potential implication of zinc as an atheroprotective agentAm J Clin Nutr · PMID 20427734
  40. Oral zinc supplementation does not improve oxidative stress or vascular function in patients with type 2 diabetes with normal zinc levelsAtherosclerosis · PMID 21840002
  41. New insights about iron bioavailability inhibition by zincNutrition · PMID 17350802
  42. Effect of fatiguing bicycle exercise on thyroid hormone and testosterone levels in sedentary males supplemented with oral zincNeuro Endocrinol Lett · PMID 17984944
  43. Zinc may regulate serum leptin concentrations in humansJ Am Coll Nutr · PMID 9627914
  44. Oral zinc sulphate in the treatment of recalcitrant viral warts: randomized placebo-controlled clinical trialBr J Dermatol · PMID 11952542
  45. Topical zinc sulphate solution for treatment of viral wartsSaudi Med J · PMID 17768472
  46. The efficacy of zinc supplementation on outcome of children with severe pneumonia. A randomized double-blind placebo-controlled clinical trialIndian J Pediatr · PMID 21660402
  47. Efficacy of zinc given as an adjunct in the treatment of severe and very severe pneumonia in hospitalized children 2-24 mo of age: a randomized, double-blind, placebo-controlled trialAm J Clin Nutr · PMID 23636236
  48. Two weeks of zinc administration to Nepalese children with pneumonia does not reduce the incidence of pneumonia or diarrhea during the next six monthsJ Nutr · PMID 20631326
  49. Role of zinc in severe pneumonia: a randomized double bind placebo controlled studyItal J Pediatr · PMID 22856593
  50. A randomized controlled trial of oral zinc in acute pneumonia in children aged between 2 months to 5 yearsIndian J Pediatr · PMID 21660397
  51. Zinc adjunct therapy reduces case fatality in severe childhood pneumonia: a randomized double blind placebo-controlled trialBMC Med · PMID 22316073
  52. A randomized controlled trial of the effect of zinc as adjuvant therapy in children 2-35 mo of age with severe or nonsevere pneumonia in Bhaktapur, NepalAm J Clin Nutr · PMID 20375190
  53. A randomized controlled trial of zinc as adjuvant therapy for severe pneumonia in young childrenPediatrics · PMID 22392179
  54. Normalization of zinc intake enhances neurological retrieval of patients suffering from ischemic strokesNutr Neurosci · PMID 19761652
  55. The role of zinc in the treatment of tinnitusOtol Neurotol · PMID 12544035
  56. The effect of exhaustion exercise on thyroid hormones and testosterone levels of elite athletes receiving oral zincNeuro Endocrinol Lett · PMID 16648789
  57. Multicenter randomized comparative double-blind controlled clinical trial of the safety and efficacy of zinc gluconate versus minocycline hydrochloride in the treatment of inflammatory acne vulgarisDermatology · PMID 11586012
  58. Oral zinc sulphate therapy in acne vulgaris: a double-blind trialActa Derm Venereol · PMID 6163281
  59. Low doses of zinc gluconate for inflammatory acneActa Derm Venereol · PMID 2575335
  60. Oral zinc in acne vulgaris: a clinical and methodological studyActa Derm Venereol · PMID 82356
  61. Failure of zinc gluconate in treatment of acute upper respiratory tract infectionsAntimicrob Agents Chemother · PMID 2665639
  62. Elevated intakes of zinc in infant formulas don not interfere with iron absorption in premature infantsJ Pediatr Gastroenterol Nutr · PMID 9740203
  63. Zinc supplementation for improving pregnancy and infant outcome.Cochrane Database Syst Rev · PMID 33724446
  64. Zinc supplementation for the promotion of growth and prevention of infections in infants less than six months of age.Cochrane Database Syst Rev · PMID 32266964
  65. Effect of enteral zinc supplementation on growth and neurodevelopment of preterm infants: a systematic review and meta-analysisJ Perinatol · PMID 34006967
  66. Effects of low dose zinc supplementation on biochemical markers in non-alcoholic cirrhosis: a randomized clinical trialArch Iran Med · PMID 22827782
  67. The effect of zinc sulfate in the prevention of high-dose chemotherapy-induced mucositis: a double-blind, randomized, placebo-controlled studyHematol Oncol · PMID 21692101
  68. Treatment of localized psoriasis with a topical formulation of zinc pyrithioneActa Dermatovenerol Alp Panonica Adriat · PMID 22367374
  69. Supplemented zinc does not alter mood in healthy older European adults--a randomised placebo-controlled trial: the Zenith studyPublic Health Nutr · PMID 21272413
  70. Impact of oral zinc therapy on the level of sex hormones in male patients on hemodialysisRen Fail · PMID 20446777
  71. Effects of zinc supplementation on serum zinc and C-reactive protein concentrations in hemodialysis patientsJ Ren Nutr · PMID 19541504
  72. Zinc for attention-deficit/hyperactivity disorder: placebo-controlled double-blind pilot trial alone and combined with amphetamineJ Child Adolesc Psychopharmacol · PMID 21309695
  73. A randomized double-blind, placebo-controlled trial of zinc sulfate supplementation for alleviation of radiation-induced oral mucositis and pharyngitis in head and neck cancer patientsJ Med Assoc Thai · PMID 23720981
  74. Evaluation of the efficacy of zinc sulfate in the prevention of chemotherapy-induced mucositis: a double-blind randomized clinical trialArch Iran Med · PMID 22724877
  75. Evaluation of oral zinc sulfate effect on obsessive-compulsive disorder: a randomized placebo-controlled clinical trialNutrition · PMID 22465904
  76. A randomized, placebo controlled trial of oral zinc for chemotherapy-related taste and smell disordersJ Pain Palliat Care Pharmacother · PMID 22764846
  77. The effect of systemic zinc supplementation on oral health in low socioeconomic level childrenTurk J Pediatr · PMID 20112596
  78. Zinc sulfate for relief of pruritus in patients on maintenance hemodialysisTher Apher Dial · PMID 22458392
  79. Efficacy of exogenous oral zinc in treatment of patients with carbonic anhydrase VI deficiencyAm J Med Sci · PMID 10616164
  80. Zinc inhibits nonheme iron bioavailability in humansBiol Trace Elem Res · PMID 17873388
  81. Effect of increasing concentrations of zinc on the absorption of iron from iron-fortified milkBiol Trace Elem Res · PMID 22760642
  82. Oral zinc for treating diarrhoea in children.Cochrane Database Syst Rev · PMID 27996088
  83. Oral zinc supplementation for the treatment of acute diarrhea in children: a systematic review and meta-analysis.Nutrients · PMID 24284615
  84. Zinc supplementation for treating diarrhea in children: a systematic review and meta-analysis.Rev Panam Salud Publica · PMID 23764669
  85. Zinc supplementation for acute and persistent watery diarrhoea in children: A systematic review and meta-analysis.J Glob Health · PMID 39641338
  86. Zinc for the prevention or treatment of acute viral respiratory tract infections in adults: a rapid systematic review and meta-analysis of randomised controlled trialsBMJ Open · PMID 34728441