risk of type 2 diabetes in observational studies, but evidence from trials is lacking. Objective:
We determined whether vitamin D supplementation, with or without calcium, improved
glucose homeostasis in adults at high risk of diabetes. Design: Ninety-two adults were
randomly assigned in a 2-by-2 factorial-design, double-masked, placebo-controlled trial to
receive either cholecalciferol (2000 IU once daily) or calcium carbonate (400 mg twice daily) …