Vitamin D has the net effect of increasing the serum calcium and phosphate concentrations by:
1- By increasing intestinal calcium and phosphate absorption and reabsorption from the kidney.
2- increasing the effect of parathyroid hormone (PTH) on bone.
Controls parathyroid gland growth and production of the parathyroid hormone.
Treatment of rickets and osteomalacia.
It is an immunomodulator.
Regulation of insulin production.
It is required for female reproduction.