Effect of fat on serum 25-hydroxyvitamin D levels after a single oral dose of vitamin D in young healthy adults: a double-blind randomized placebo-controlled study.

Purpose: This double-blind placebo-controlled trial evaluated serum 25-hydroxyvitamin D [25(OH)D] levels after the oral intake of a single dose of cholecalciferol during one of the three meals, containing different amounts of fat or placebo.

Methods And Results: Sixty-four healthy medical residents or students of a university hospital in Porto Alegre, latitude 30° S, Brazil, were divided into four groups. Three groups received a single 50,000 IU oral dose of cholecalciferol during a meal containing 0 g (Group 1), 15 g (Group 2) or 30 g (Group 3) of fat, and one group received placebo (Group 4), according to randomization.