Nutritional requirements in cystic fibrosis: a review.

Food intake is often low in cystic fibrosis (CF), although the patient usually needs more than the standard recommended daily allowance (RDA). Clinics giving food supplementation from an early age report improved survival and nutritional status. Nutritional improvement has been facilitated by improved forms of pancreatin. An additional calorie intake in CF is required to compensate for losses due to malabsorption and to allow for catch-up growth when necessary. With advanced pulmonary disease there are additional requirements for infection and increased work of breathing. There is also evidence for an increased basal metabolic activity in CF, perhaps related to the fundamental intracellular biochemical disorder. Together these factors add to a daily need for 120%-150% RDA for optimum growth and homeostasis.