The nutritional essential forms of Vitamin D in an average built man are Vitamin D 2 (medically known as Calceferol) and Vitamin D 3 (medically known as cholecalciferol). Calciferol can be derived by actinotherapy of the plant sterol and ergosterol whereas the cholecalciferol is all natural occurring performed Vitamin D that is present in animal sources (mainly fats and various fish liver oil). It can also be derived when we expose to Ultraviolet rays of the sunrays that converts the cholesterol present in the skin in vitamin D. Vitamin D is fat soluble and therefore, it is stored in the fatty cells.
Vitamin D Sources: Vitamin D is very essential since it is derived both; from sunrays and also from edible items. Let us look at both of them:-
Sunrays: Vitamin D is synthesized in the body with the help of Ultra violet rays of sun in the form of 7 dehydrocholesterol that is stored in great amounts in the skin. Proper exposure to Ultra violet rays is quite critical since this could be filtered off by the pollution present in the atmosphere. For a particular race i.e. people having darkened skin like Negroes may suffer from this disfavor as black skin generally filters off up to 93 per cent of UV (ultra violet) rays.
Edibles: Vitamin D can be supplied only by the foods except from sun exposure but the foods that are of animal origin. Animal sources such as liver, some special species of fishes, egg yolk and dairy products (again, animal origin) such as butter and cheese contain adequate amounts of Vitamin D. Fish liver oils, though not believed to be among foods, are found to be the richest source of Vitamin D.
Daily requirement: The recommended daily dose for vitamin D depends upon the age and are mentioned below:-
Adults - 2.5 mcg (100 IU)
Infants and children - 5.0 mcg (200 IU)
Pregnancy and lactation - 10.0 mcg (400 IU)
(Note: IU is International Unit. One IU of vitamin D is equal to 0.025 mg of calciferol. This is obtained by converting IU to micrograms i.e. divided by 40).
Recent studies show that human milk contains substantial amounts of water-soluble vitamin D sulfate. However, other sources of vitamin D include the foods fortified (artificially filled) with vitamin D like margarine, ghee and some specially made baby supplements/foods.
