25‐Hydroxyvitamin D Threshold for the Effects of Vitamin D Supplements on Bone Density: Secondary Analysis of a Randomized Controlled Trial

Most trials of vitamin D supplementation have shown no benefits on bone mineral density (BMD), although severe vitamin D deficiency causes osteomalacia, which is associated with profound BMD deficits. Recently, the ViDA-BMD study from New Zealand demonstrated a threshold of baseline 25-hydroxyvitamin D (25OHD; 30 nmol/L) below which vitamin D supplementation did benefit BMD. We have now reexamined data from a similar trial in Aberdeen to...