Response to oral beta-carotene supplementation in patients with cystic fibrosis: a 16-month follow-up study

Abstract

The aim of this study was to determine the efficacy of long-term oral beta-carotene supplementation for correcting impaired beta-carotene status in cystic fibrosis patients. Thirty-five patients (2.3-30.5 years of age) with coefficients of fat absorption of 46-96% (median 88%) received beta-carotene 0.5 mg/kg daily and were followed over a 16-month treatment period. Baseline plasma beta-carotene concentrations in patients (mean +/- SD, 0.09 +/- 0.06 mumol/l) were significantly lower than those of age-matched controls (0.86 +/- 0.56 mumol/l) (p < 0.0001). Concentrations increased rapidly and reached a plateau at or before 3 weeks that was maintained throughout the study period. Values obtained at 3 weeks (0.89 +/- 0.64 mumol/l) were significantly higher (p < 0.0001) than those at baseline and did not differ from controls. Plasma retinol and alpha-tocopherol concentrations increased during the observation period, but remained within normal ranges. Plasma retinyl palmitate, which was below the detection limit in all but one patient at baseline, did not increase. Thus oral beta-carotene supplementation is effective and normalizes beta-carotene status of cystic fibrosis patients without evidence of significant side effects.