Abstract
Background: There is much interest in dosing vitamin D intermittently for patient convenience and long-term adherence. Objective: The objective was to characterize the time course and response of 25-hydroxyvitamin D (calcidiol) to a large oral dose of cholecalciferol. Design: One group (30 subjects) was supplemented with a single oral dose of 100 000 IU cholecalciferol. A second group (10 subjects) served as a control group to assess the seasonal change of calcidiol. Serum calcidiol concentrations were followed for 4 mo. The subjects were healthy with limited sun exposure (