Cystic Fibrosis and Vitamins

Vitamins are essential for growth and to support numerous metabolic processes in the human body. Vitamin deficiency can be caused by many factors, such as inadequate diet or increased requirements due to pregnancy or lactation, drug use, or disease.

Vitamins for cystic fibrosis patients

Many patients with cystic fibrosis (CF) have a pancreatic insufficiency that is characterized by problems in releasing digestive enzymes. Therefore, pancreatic enzyme replacement therapy (PERT) can help patients to absorb nutrients from food more efficiently. PERT contains the enzymes lipase, protease, and amylase in capsule form, which are taken before eating and work for about 45 to 60 minutes.

Appropriate dosing of lipase, a fat-digesting enzyme, is important because CF patients have problems absorbing fats, making them prone to developing deficiencies in fat-soluble vitamins (vitamins A, D, E, and K). However, even though PERT helps to absorb more of these vitamins, CF patients are advised to take fat-soluble vitamin supplements.

CF patients should supplement with the right amount of vitamins, because good nutritional status is associated with improved lung function and survival.  

Vitamin A

Vitamin A helps improve vision, cell function, immunity, and intestinal health. It also promotes bone and tooth formation, and protects against infections.

The active form of vitamin A, also known as retinol, is only found in animal products — liver is the best source. An inactive form of vitamin A, beta-carotene, is in yellow fruits and vegetables. Beta-carotene is less bioavailable than retinol because the body has to convert it into retinol before using it.

In CF patients, good vitamin A levels are correlated with improved lung function. It is not entirely understood how vitamin A increases lung function in CF patients, but it is known that the vitamin has an essential role in maintaining the health of the inner lining of the lungs.

Vitamin A is also needed to fight against infections and may, therefore, protect against damage from lung infections. It has antioxidant properties, which protect against oxidative damage in the lungs.

Vitamin A supplementation is recommended but must be undertaken carefully because the vitamin is toxic at high doses, and can cause liver and bone problems.

Vitamin D

Vitamin D plays a vital role in the formation and maintenance of healthy bones and teeth.

The vitamin is formed when skin is exposed to ultraviolet light. Sufficient sunlight exposure is needed to make enough vitamin D when it is not taken as a supplement. The vitamin is also found in fatty fish.

Vitamin D deficiency is prevalent among CF patients. Low vitamin D levels reduce the calcification of bones, and therefore contribute to the osteoporosis frequently observed in this group of patients.

Vitamin E

An antioxidant, vitamin E protects the body against harmful oxidative damage. It also improves the health of red blood cells, helps combat infections, and maintains proper intestinal function.

Vegetable oils, eggs, and nuts are good sources of vitamin E.

Vitamin E deficiency occurs frequently in CF patients. Low levels of vitamin E can cause anemia or a decreased number of red blood cells, so supplementation with this vitamin is recommended to increase hemoglobin levels (the oxygen-carrying protein in red blood cells) in children with CF.

Vitamin K

Vitamin K promotes blood clotting and helps to maintain bone health. It’s produced by bacteria in the gut.

The frequent use of antibiotics, which destroys gut bacteria, is thought to cause vitamin K deficiency in CF patients. Low levels of vitamin K can cause coagulation abnormalities, leading to hemorrhagic episodes.


Cystic Fibrosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.