The calcium endocrine system

The role of calcium as a modulator of a large number of physiological processes is well known. It is not surprising that the two principally in the understanding of its subcellular physiology and molecular biology. There is new knowledge on hepatocellular uptake of vitamin D. The subsequent hepatic conversion of vitamin D to 25 hydroxy vitamin D may indeed be under the feedback control of the active vitamin D, 1,25 dihydroxyvitamin D. Vitamin D now also appears to have many new and diverse functions some of which already have clinical application.