Vitamin D is metabolized into a potent steroid hormone called calcitriol. More recently, it has become clear that receptors for calcitriol, are present in a wide variety of cells and that calcitriol has biologic effects which extend far beyond control of mineral metabolism.
It is believed that vitamin D and its metabolites play an important part in the regulation of genes involved in cell growth, differentiation and proliferation. By promoting differentiation and inhibiting proliferation, vitamin D may become an important factor in cancer prevention and therapy.
Through its regulation of genes, calcitriol controls the production of immune factors known as lymphokines, which effect cell-mediated immunity functions.
What is vitamin D used for?
Vitamin D may prevent autoimmune disease, osteoporosis, and some pulmonary conditions. Vitamin D deficiency is common in the higher latitudes. It helps the body to absorb calcium for bones and teeth.
How safe is vitamin D?
Oral vitamin D is very well tolerated. High doses may interfere with the activity of certain statin drugs used to treat elevated cholesterol.