Prospective, long-term study of fat-soluble vitamin status in children with cystic fibrosis identified by newborn screen.

OBJECTIVE: To prospectively evaluate the biochemical status of vitamins A, D, and E in children with cystic fibrosis (CF). SUBJECTS: A total of 127 infants identified by the Colorado CF newborn screening program. DESIGN: Vitamin status (serum retinol, 25-hydroxy vitamin D, ratio of alpha-tocopherol/total lipids) and serum albumin were assessed at diagnosis (4 to 8 weeks), ages 6 months, 12 months, and yearly thereafter, to age 10 years. RESULTS: Deficiency of 1 or more vitamins was present in 44 (45.8%) of 96 patients at age 4 to 8 weeks as follows: vitamin A 29.0%, vitamin D 22.5%, and vitamin E 22.8%. Of these patients with initial deficiency, the percent that was deficient at 1 or more subsequent time points, despite supplementation, was vitamin A 11.1%, vitamin D 12.5%, and vitamin E 57.1%. Of the initial patients with vitamin sufficiency, the percent who became deficient at any time during the 10-year period was as follows: vitamin A 4.5%, vitamin D 14.4%, and vitamin E 11.8%. The percent of patients deficient for 1 or more vitamins ranged from 4% to 45% for any given year. CONCLUSIONS: Despite supplementation with standard multivitamins and pancreatic enzymes, the sporadic occurrence of fat-soluble vitamin deficiency and persistent deficiency is relatively common. Frequent and serial monitoring of the serum concentrations of these vitamins is therefore essential in children with CF.

Enteral nutrition for patients with cystic fibrosis: comparison of a semi-elemental and nonelemental formula.

OBJECTIVE: To determine whether differences in tolerance and absorption of fat and nitrogen exist between a semi-elemental nutritional formula without enzyme replacement and a nonelemental formula with enzyme replacement. STUDY DESIGN: Sixteen patients (eight girls and eight boys) with cystic fibrosis, 4 to 20 years of age (12+/-1.3, mean +/- SEM), who were pancreatic insufficient completed two 6-day regimens of nocturnal continuous enteral feedings offered in random order. Forty-four percent of the total daily energy was consumed as enteral tube feedings, and the remaining oral dietary intake remained constant throughout the study. Seventy-two-hour fecal collections from each study period were analyzed for total fat, long-chain fatty acids (LCFAs), medium-chain fatty acids (MCFAs), and nitrogen. RESULTS: Fat absorption was 80.2%+/-2.9% and 82.3%+/-3.1% (p = 0.58) for the semi-elemental and nonelemental formulas, respectively. Similarly, the coefficient of absorption of LCFAs was 69.5%+/-4.5% and 79.6%+/-3.4% (p = 0.30) for the semi-elemental and nonelemental formulas. Malabsorption of MCFAs contributed minimally to total fat malabsorption. There was no difference between formulas for MCFA or for nitrogen absorption, 83.7%+/-1.9% and 87.4%+/-1.4%, p = 0.48. All patients tolerated all feedings, and weight gained was 1.8+/-0.3 kg with no difference in weight gain between the trials. CONCLUSION: A nonelemental formula, with enzyme replacement, is absorbed as well as a predigested formula in patients with CF who are pancreatic insufficient.