Vitamin D is a hormone precursor that contributes to the maintenance of normal levels of calcium and phosphorus in the blood. Despite its name, vitamin D is not a true vitamin, but it could best be described as a conditional vitamin, since human skin can create it in some circumstances. Vitamin D is also known as calciferol.

Overview

Vitamin D plays an important role in the maintenance of an intact and strong skeleton. Its primary task is to regulate the amount of calcium and phosphorus in the blood by ensuring correct intake and secretion (from intestines and urine, respectively).