Vit D Discussion Wheeless

Description: primary function of vitamin D is to maintain skeletal calcium homeostasis;
- promotes gut absorption of calcium (and absorption of phosphorous);
- promotes bone absorption;
- important for maintaining adequate quantities of Ca & Phos for bone formation thru its effects on the kidney & gut;
- in addition, it may have a direct effect on bone formation;
- proper functioning of the vitamin D system is necessary for PTH to maintain plasma calcium effectively, although drops in the plasma Ca occur only with severe Vit D depletion;
- it appears that only minute amounts of Vit D are necessary for PTH to carry out its actions on the bone and kidney
Wheeless' Textbook of Orthopaedics