Category:Vitamin D

From Ganfyd

This includes a range of compounds used at different doses prophylactically and therapeutically in Vitamin D deficiency (osteomalacia/rickets). Vitamin D compounds play an important role in calcium homeostasis. As a fat-soluble vitamin, it is stored in the liver. They have the potential for toxicity at high, prolonged doses with the induction of hypercalcaemia and are perhaps best classed as hormones as actually, with enough sunlight, the body can meet its own needs.

The therapeutic indications for the various Vitamin D compounds differ, reflecting the metabolism of Vitamin D and perhaps that they are slighly different hormones, with effects on more than just calcium metabolism. Alphacalcidol is the compound of choice in renal failure. Ergocalciferol (Calciferol) is used in osteomalacia or rickets. The only low dose oral Vitamin D compound demonstrated to reduce osteoporotic fractures in the institutionalised elderly is colecalciferol. Perhaps this is because of its effects on muscle function.

Rarely amongst vitamins, Vitamin D supplementation without an overt deficiency state (except osteoporosis?) may be associated with reduced mortality^[1].

Measuring Vitamin D levels in the blood can be useful clinically but comes with several caveats:

1. Levels are seasonal (lowest in winter)
2. Levels are a function of at least 3, and possibly 4 genes coding for 7-DHC reductase, 25-hydroxylase CYP2R1, CYP24A1 and the vitamin D binding-protein and it is unknown how and if this needs correcting for as of 2010

References