Vitamin D is unique because it is the only conditional vitamin. Vitamin D is known as the “sunshine” vitamin. It is formed in the body by the action of the sun’s ultraviolet rays on the skin. Where humans are not exposed to enough sunlight, supplemental intake of vitamin D is required. Under such conditions vitamin D is considered an essential human nutrient.

Plays an essential role in:

§          Involved in both the formation (mineralization) of bone. Vitamin D  is the primary regulator of calcium in the body and is vital to proper skeletal development and bone mineralization.

§          in strengthening the body's immune system,

§          assisting blood cell formation.

§          There is new evidence to suggest that Vitamin D plays a role in neuromuscular functioning in older adults It is believed that vitamin D may protect people from a number of other conditions including multiple sclerosis, autoimmune arthritis, and juvenile diabetes.

Vitamin D deficiency

Vitamin D deficiency can result from inadequate dietary intake, insufficient exposure to sunlight, which reduces the body’s synthesis of vitamin D, and kidney or liver malfunctions, which inhibit the conversion of vitamin D to its metabolically active forms
Vitamin D deficiency is characterized by poor mineralization or demineralization of the skeleton. Abnormally low mineralization of the human skeleton is what causes rickets in children, while demineralization of the skeleton causes osteomalcia in adults. Vitamin D deficiency can also lead to osteoporosis which occurs when the body begins to reabsorb bone.


Click here for Vitamin D RDA  table

Vitamin D Forms
Vitamin D2 (ergocalciferol), vitamin D3 (cholecalciferol), calcitrol (1,25 dihydroxy cholecalciferol).