Description
25-hydroxyvitamin D2 (25-OH D2) is a metabolic product of ergocalciferol, or vitamin D2, an exogenously produced vitamin D dietary supplement. 25-OH D2 restores bone mineralization in vitamin D-deficient models and also regulates Ca2+ homeostasis as a downstream effect of the vitamin D signaling cascade. 25-OH D3 binds to the vitamin D receptor (VDR) but with lower affinity that 25-hydroxyvitamin D3 (25-OH D3). Potential mechanisms remain unknown, but low levels of 25-OH D2 are associated with Alzheimer’s disease in some studies.