Abnormalities Associated With Vitamin D


- See:
       - Vit D - Discussion:
       - Calcitriol/Rocalrol/Calcifediol:

- Discussion:
    - primary function of  l,25-Vitamin D3 is to maintain skeletal homeostasis as well as for maintenance of plasma Ca homeostasis;
           - primary effect of lack of Vit D is decrease in miceralization of newly formed bone matrix (osteoid);
           - rate of bone formation is decreased;
           - net result is less total bone & marked change in quality of bone;
    - only minute amounts of vitamin D are necessary for parathyroid hormone to carry out its actions on bone and kidney;
    - osteomalacia, group of dz, characterized by defective mineralizaiton can be caused by any problem resulting in inadequate amounts of Vit D or low PO4;
           - in osteomalacia defective mineralizaiton results in relative increase in amount of osteoid  (unmineralized bone matrix) in bone;

- Vitamin D Discussion:
    - persons who do not receive adequate daily sunlight exposure, such as those confined to home or nursing facility, may be at special risk for vitamin D deficiency;
    - decrease in mineralization of newly formed bone matrix (osteoid);
          - rate of bone formation is decreased;
          - net result is less total bone & marked change in quality of bone;
    - osteomalacia:
          - defective mineralization results in relative increase in amount of osteoid (unmineralized bone matrix) in bone;
    - in skeletally immature individuals, mineralization in growth plates is also affected;
          - osteomalacia in this setting is called rickets (Vitamain D Deficient Rickets)
          - impaired mineralization of cartilage in the zone of calcification arrests enchondral ossification & prevents formation of the primary spongiosa;

     - Vitamin D Resistant Rickets



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, May 5, 2011 1:10 pm