Vitamin D2 Is Much Less Effective than Vitamin D3 in Humans
Given the literal explosion of Vit D research over the past few years, this information is of great importance. Many of the lower quality multivitamins contain the D2 form of Vit D which (ergocalciferol=D2, cholecalciferol=D3) in this study was about 1/3 as potent and its effect was much shorter. Yet another reason why spending a little extra money on a good quality multi is not just “making expensive urine.”
Vitamin D2 Is Much Less Effective than Vitamin D3 in Humans — Armas et al. 89 (11): 5387 — Journal of Clinical Endocrinology –