Vitamin D toxicity related to its physiological and unphysiological supply

Vitamin D is defined as a micronutrient, yet very few foods contain more than a trace of vitamin D. Solar UV light induces vitamin D formation in skin, and surveys have demonstrated that vitamin D status is determined mainly by this method. The amount of vitamin D produced in skin is far greater than could be obtained from natural foods. Potential toxicity of vitamin A, a true micronutrient, is prevented by esterification or by binding to...