Research Shows Benefit from Vitamin C Supplements for Cystic Fibrosis

Cystic fibrosis (CF) is the most common lethal inherited disease in white persons.  Cystic fibrosis is an autosomal recessive disorder, and most carriers of the gene are asymptomatic.

Cystic fibrosis is a disease of exocrine gland function that involves multiple organ systems but chiefly results in chronic respiratory infections, pancreatic enzyme insufficiency, and associated complications in untreated patients (see Clinical). Pulmonary involvement occurs in 90% of patients surviving the neonatal period. End-stage lung disease is the principal cause of death.

Cystic fibrosis is a genetic disease that is associated with increased inflammation, and like many inflammatory diseases, it comes with a large amount of oxidative stress.

Oxidative stress happens because of an imbalance in the body between free radicals, which can cause harmful chemical reactions, and antioxidants. Antioxidants are molecules able to give an electron to a free radical, causing the free radical to become less reactive without becoming unstable themselves.

In addition to oxidative stress, cystic fibrosis is also characterized by problems with fat absorption, which limits uptake of vitamin E, a fat-soluble antioxidant. Low vitamin E levels plus high oxidative stress is a recipe for more inflammation, which can contribute to a range of negative health outcomes.

Patients’ difficulties with fat absorption mean that they need to consume larger than usual amounts of fat-soluble vitamins like vitamin E. Patients need at least 400 milligrams of vitamin E daily to achieve normal blood concentrations.

Research shows benefit from vitamin C supplements for Cystic Fibrosis

In this study, the researchers looked at whether vitamin C supplements could help patients better use their absorbed vitamin E. Vitamin C can recycle oxidized forms of vitamin E, and it is also helpful at tamping down the oxidative stress aspects of inflammation.

After 3½ weeks of daily 1,000-milligram doses of vitamin C, the patients in the study trended toward lower blood concentrations of a key oxidative stress biomarker, malondialdehyde or MDA, and also toward a slowdown in vitamin E elimination from the bloodstream.

Since vitamin E is hanging around longer, it might be able to get into tissues better, and better protect cell membranes from oxidative stress.

This study used vitamin C far in excess of what someone can easily obtain from the diet, one thousand milligrams is the equivalent of 15 oranges or four or five medium bell peppers. But the research does suggest a high dosage may be beneficial in inflammatory conditions.

Smokers, for example, typically have problems associated with oxidative stress and can benefit from extra vitamin C and possibly extra vitamin E. Metabolic syndrome patients have issues with vitamin C and E as well.


Maret G. Traber, Scott W. Leonard, Vihas T. Vasu, Brian M. Morrissey, Huangshu (John) Lei, Jeffrey Atkinson, Carroll E. Cross (September 9, 2022). α-Tocopherol Pharmacokinetics in Adults with Cystic Fibrosis: Benefits of Supplemental Vitamin C Administration. Nutrients. Retrieved from :