In the last time we have a lot off citation about vitamin D. This is because we recognize its importance for health and secondly because science is discovering new activities of this important vitamin and its metabolites that already have a number of hormone properties.
A good indicator of the vitamin D status in the body is plasma calcidiol concentration expressing vitamin D from food, exposure of the skin to the sun, and conversion of vitamin D from the fat stores in the liver. The essential effects of vitamin D include is its effects on calcium and phosphorus resorption through the intestines and the regulation of the stability of these elements in the body and finally the control of bone mineralization.
It has a positive effect on muscle mass, increases muscle protein synthesis, affects the transport of calcium and phosphorus through the cell membranes, affects the metabolism of phospholipids and contractile muscle fibers, functions of the immune system and regulates a large number of genes. Vitamin D serves as a signal molecule between cells and thus controls about 200 genes involved in cell differentiation, replication, and immunity.
Calcitriol binds to the nuclear receptor (VDR). The VDR of all tissues is the same, or calcitriol can bind to VDR wherever the receptor is expressed.
Recent studies suggest that vitamin D may prevent several chronic diseases in addition to its well established role in guts resorption of calcium and phosphate and bone metabolism. These newly detected physiological functions of vitamin D involve regulation of cell differentiation in many cells and tumor cells.
It is only a matter of time whether the other effects described are fully confirmed.