Cholecalciferol is found only in animals. The active hormonal form of vitamin D is 1,25 dihydroxycholecalciferol. The primary purpose of vitamin D is to regulate plasma levels of Ca and P to support bone mineralization. A vitamin D deficiency primarily results in rickets in children and osteomalacia in adults. Eight forms are found in nature.
Vitamin E is a natural antioxidant that helps prevent cellular damage.
The primary function of vitamin E is to maintain cell membrane integrity from oxidative damage. Good sources of vitamin E are vegetable oils, cereal products, liver and vitamin supplements. Vitamin K is known as the clotting vitamin, because without it blood would not coagulate. Some studies indicate that it helps in maintaining strong bones in the elderly. Vitamin K is used to describe several quinone compounds that helps the blood clotting process.