Background: Cystic fibrosis (CF) and pancreatic insufficiency (PI) predispose patients to fat and fat-soluble vitamin malabsorption despite pancreatic enzyme replacement. Recent evidence suggests current patterns of vitamin A supplementation may be excessive. Aims: To assess serum retinol and vitamin A intake in children and young adults with CF and PI compared to healthy subjects. Methods: Participants, 8 to 25 years old, had blood collected, growth status (height [HAZ] and weight [WAZ] Z scores) and FEV1 (% predicted) assessed. Serum retinol (μg/dL) was analyzed by HPLC and compared with age-matched reference ranges (5th and 95th %iles) for non-Hispanic white subjects from NHANES 1999-2002. Vitamin A intake (food and supplement-based, pre-formed retinol and total vitamin A) was reported in retinol activity equivalents (μg RAE) from 3-day weighed food records. Vitamin A intake was compared with Dietary Reference Intakes (DRI) and with CF recommendations. Results: Serum retinol, growth status and FEV1were available for 78 subjects and dietary intake data for 53 subjects. 42% of subjects had serum retinol within, and 58% above the reference range (30 to 72 μg/dL). Total vitamin A intake (mean ± sd; μg RAE/d) was 608 ± 431% of the Recommended Dietary Intake (RDA); 67% from supplements. Preformed retinol intake was 564 ± 409 %RDA. 86% of subjects had total preformed retinol intake above the DRI Tolerable Upper Limit of Intake, and 73% above CF recommendations. Serum retinol was inversely correlated with HAZ and WAZ (r = −0.28 for both, P < 0.05), but not associated with FEV1, age or gender. Conclusions: Elevated serum retinol levels and excessive preformed vitamin A intake raise concerns regarding the use, dose, and formulation (preformed, water miscible) of vitamin A supplements in CF care. The possibility of and risk for vitamin A toxicity require further study. Supported by R01 HL57448, GCRC (5-M01-RR00240), and Nutrition Center at CHOP, and the CF Foundation.