Vitamin D intake to attain a desired serum 25-hydroxyvitamin D concentration.

Background: Indirect evidence suggests that optimal vitamin D status is achieved with a serum 25-hydroxyvitamin D [25(OH)D] concentration >75 nmol/L.

Objective: We aimed to determine the intake of vitamin D(3) needed to raise serum 25(OH)D to >75 nmol/L.

Design: The design was a 6-mo, prospective, randomized, double-blinded, double-dummy, placebo-controlled study of vitamin D(3) supplementation.