Effect of Vitamin D2 Supplementation on 25-Hydroxyvitamin D3 Status: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Researchers have identified differences in metabolic activity between vitamins D2 and D3. Moreover, it is suspected from randomized controlled trial data that vitamin D2 supplementation increases the metabolic clearance of 25-hydroxyvitamin D3 [25(OH)D3], but this effect has yet to be quantified.