Vitamin D

Vitamin D

The proper chemical name of vitamin D is Calciferol. For most people enough vitamin D can be made by the action of sunlight on the skin. The light-absorbing molecule found in the skin is made from cholesterol. The active part of the light is ultraviolet light. Normally, stores of vitamin D build up in the liver in the summer months and provide the body's requirements during the rest of the year. Except the principle sources listed below most natural foods are low in vitamin D. So these days vitamin D is added as a supplement to some foods, such as margarine and breakfast cereals.

Principle Sources

Fish-liver oil

Liver

Egg yolk

Dairy products

Margarine

Tuna

Vitamin D fortified milk

Made by the action of sunlight on a cholesterol like compound in the skin.

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Function

Controls calcium absorption from the gut, and concerned with calcium metabolism. Important in bone and tooth formation.

Aids absorption of phosphorus.

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Deficiency diseases and Symptoms

Rickets-This is the failure of growing bones to calcify. Bow legs are a common children and knock knees in older ones. Deformation of the pelvic bones in adolescent girls can occur which may lead to complications when they are pregnant, and give birth.

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Osteomalacia-An adult condition where the bones are painful and spontaneous fractures may occur. Here the bones are weakened and soften, becoming less mineralised with calcium and phosphate.

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Excess Vitamin D?

Excess intake of vitamin D can lead to excess calcium uptake. If the excess cannot all be excreted in the urine it may become deposited in the kidneys where it can cause damage. It is more dangerous for infants than for adults.

Right Amount you Should Take

Regular intakes should not exceed;

35mg per day for teenagers

40mg per day for adolescent

40mg per day for adult women

40mg per day for adult men

50mg per day for pregnant lady

70mg per day for lactating women