In a patient with cystic fibrosis, which vitamin supplementation is most important?

• A. Vitamin B vitamins
• B. Vitamin C
• C. Vitamin D
• D. Vitamin A

Answer: (D)

Cystic fibrosis often causes pancreatic exocrine insufficiency, leading to poor absorption of fats and fat-soluble vitamins A, D, E, and K. Among these, vitamin A deficiency most directly affects vision and epithelial integrity; night blindness and corneal changes can develop if it is not supplemented. That makes vitamin A supplementation particularly important in CF. While vitamins D, E, and K are also necessary to address due to fat-malabsorption, the immediate clinical impact of vitamin A deficiency—especially on vision—tavors prioritizing its supplementation.