25-OH-D3 stands for 25-Hydroxy calcifediol, which is also known as cholecalciferol and is the main form of vitamin D present in our bodies. Vitamin D is made by the skin when it is exposed to ULTRAVIOLET light, but in small amounts it is obtained from food or other supplements. The 25-hydroxy calcifediol content, which determines the level of vitamin D in our bodies, is high in the blood, as the 25-hydroxy calcifediol is stable and will not be affected by diet or lifestyle, The half-life is long, usually two to three weeks, so the levels of vitamin D in the blood are determined by the 25-hydroxy calcifediol levels.
25-hydroxy calcifediol is the conversion of vitamin D in the liver through hydroxylation and by the kidney to active 1, 25-dihydroxyvitamin D, the main active form of vitamin D. Otherwise, kidney abnormalities may interfere with vitamin D use.
