Calcifediol

vitamin · digestive · renal · Oral

Calcifediol, a vitamin. The 25-hydroxy metabolite of cholecalciferol — bypasses the hepatic CYP2R1 hydroxylation step, so it raises serum 25(OH)D… Oral half-life 15 d.

The 25-hydroxy metabolite of cholecalciferol — bypasses the hepatic CYP2R1 hydroxylation step, so it raises serum 25(OH)D faster and more predictably than D3 (Tmax ~4 h vs ~12 h; ~3× steeper 25(OH)D response slope). Water-soluble after hydroxylation, so does not partition into adipose — useful in obesity and malabsorption where D3 has attenuated response. Still requires renal CYP27B1 to reach 1,25(OH)₂D.

Pharmacokinetics

• Oral — t½ 15.0 d · F 100% · Vd 10.5 L

Related compounds

• Vitamin D3 — synergistic
• Magnesium — synergistic

Sources: PMID:24516879, PMID:3260278