Condition

Cystic Fibrosis

Cystic fibrosis is a genetic condition in which thick, sticky mucus clogs the airways and keeps digestive enzymes from reaching the intestines. Pancreatic enzymes and vitamin D have the strongest evidence for supporting nutrition, and a trial found vitamin E raised blood vitamin E levels. That vitamin E evidence is limited, from one small study, and probiotics showed no clear difference in symptoms.

Sources: PMID 32892350

Supplements studied: 7
Graded outcomes: 4
Trials: 4
People studied: 1,418

Evidence by supplement

Strong
Moderate
Limited
Very limited

7 supplements

Vitamin E

Vitamin E: outcomes studied for Cystic Fibrosis
Grade	Outcome	Effect	Size	Studies	People
	Plasma Vitamin E Small Increase	Improves (the measure goes up)	Small effect	1 study	141 people
Studies that measured plasma vitamin e Vitamin E supplementation in people with cystic fibrosis.Cochrane Database Syst Rev · PMID 32892350
	Weight	Improves (the measure goes down)		1 study	141 people
Studies that measured weight Vitamin E and respiratory tract infections in elderly nursing home residents: a randomized controlled trialJAMA · PMID 15315997

Lactobacillus reuteri

Lactobacillus reuteri: outcomes studied for Cystic Fibrosis
Grade	Outcome	Effect	Size	Studies	People
	Cystic Fibrosis Symptoms Small Improvement	Improves (the measure goes down)	Small effect		120 people
	Lung Function	Improves (the measure goes up)		1 study	60 people
Studies that measured lung function Improvement of digestive health and reduction in proteobacterial populations in the gut microbiota of cystic fibrosis patients using a Lactobacillus reuteri probiotic preparation: a double blind prospective studyJ Cyst Fibros · PMID 24636808
	TNF-Alpha	Improves (the measure goes down)		1 study	60 people
Studies that measured tnf-alpha Lactobacillus reuteri ATCC55730 in cystic fibrosisJ Pediatr Gastroenterol Nutr · PMID 24121143
	Interleukin 8	Changes; see studies			60 people
	Upper Respiratory Tract Infection Risk	Changes; see studies			60 people

Creatine

Cystic Fibrosis Symptoms
Subjective Well-Being: improves

Creatine: outcomes studied for Cystic Fibrosis
Grade	Outcome	Effect	Size	Studies	People
	Cystic Fibrosis Symptoms No effect		NoneNo effect	1 study	11 people
Studies that measured cystic fibrosis symptoms Effects of creatine supplementation in cystic fibrosis: results of a pilot studyJ Cyst Fibros · PMID 15463870
	Subjective Well-Being	Improves (the measure goes up)		3 studies	11 people
Studies that measured subjective well-being Effect of creatine supplementation and sleep deprivation, with mild exercise, on cognitive and psychomotor performance, mood state, and plasma concentrations of catecholamines and cortisolPsychopharmacology · PMID 16416332 Creatine supplementation, sleep deprivation, cortisol, melatonin and behaviorPhysiol Behav · PMID 17046034 Creatine supplementation improves muscle strength in patients with congestive heart failurePharmazie · PMID 16599263

Probiotics

Cystic Fibrosis Symptoms
Fecal Calprotectin: improves
Lung Function: improves

Probiotics: outcomes studied for Cystic Fibrosis
Grade	Outcome	Effect	Size	Studies	People
	Cystic Fibrosis Symptoms No effect		NoneNo effect		258 people
	Fecal Calprotectin	Improves (the measure goes up)		1 study	177 people
Studies that measured fecal calprotectin Probiotics for people with cystic fibrosis.Cochrane Database Syst Rev · PMID 31962375
	Lung Function	Improves (the measure goes up)		1 study	284 people
Studies that measured lung function Effectiveness of Probiotics, Prebiotics, and Symbiotic Supplementation in Cystic Fibrosis Patients: A Systematic Review and Meta-Analysis of Clinical Trials.Medicina · PMID 40142300
	Quality of Life	Improves (the measure goes up)			37 people

Fish Oil

Cystic Fibrosis Symptoms: improves

Fish Oil: outcomes studied for Cystic Fibrosis
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Cystic Fibrosis Symptoms	Improves (the measure goes down)		1 study	13 people
Studies that measured cystic fibrosis symptoms The clinical benefits of long-term supplementation with omega-3 fatty acids in cystic fibrosis patients - A pilot study.Prostaglandins Leukot Essent Fatty Acids · PMID 27154364

Vitamin D

Bone turnover markers: changes; see studies

Vitamin D: outcomes studied for Cystic Fibrosis
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Bone turnover markers	Changes; see studies		1 study	91 people
Studies that measured bone turnover markers Changes in bone turnover after high-dose vitamin D supplementation during acute pulmonary exacerbation in cystic fibrosis.Bone · PMID 37390941

Synbiotics

Lung Function: improves

Synbiotics: outcomes studied for Cystic Fibrosis
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Lung Function	Improves (the measure goes up)			81 people

Key findings

Plasma Vitamin EVitamin EImproves (the measure goes up)
Cystic Fibrosis SymptomsLactobacillus reuteriImproves (the measure goes down)

The Cystic Fibrosis Nutritional Support protocol

2 primary supplements · 8 supporting supplements

Pancreatic Enzymes (PERT)500–2,500 lipase units/kg/meal (max 10,000 units/kg/day) - per CF team guidance
Vitamin D2,000–5,000 IU daily or higher based on levels (target 30–50 ng/mL)

See the full protocol

Studies cited

1 study from PubMed

Exercise versus airway clearance techniques for people with cystic fibrosis.Cochrane Database Syst Rev · PMID 35731672