Chemical Structure For Vitamin D
Vitamin D Chemical Structures Food Sources Vitamin D in the Body Stability Synthesis
Vitamin D Crystals
Vitamin D
Vitamin D, or calciferol, is the general name for a collection of steroid-like substances including vitamin D2, ergocalciferol (fig.1) and vitamin D3, cholecalciferol (fig.2). Found only in animal sources, vitamin D is fat soluble and can be manufactured by the body on exposure to UV radiation.Top
Chemical Structures
Fig.1 The Chemical Structure of Vitamin D2 (Ergocalciferol)
3D Structure of Vitamin D2
Fig.2 The Chemical Structure of Vitamin D3
Fig.3 The Chemical Structure of Calcidiol
Fig.4 The Chemical Structure of Calcitriol
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Principal Sources in Food
Vitamin D is only found naturally in animals and animal products; fruit and nuts contain no vitamin D at all. Richest sources include:- Fish liver oils, particularly those of:
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- Halibut
- Cod
- Saltwater fish, including:
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- Herring
- Mackerel
- Salmon
- Sardines
- Eel
- Milk
- Butter
- Cheese
- Margarine
- Cream
- Yoghurt
- Egg
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Vitamin D in the Body
In the body, the vitamin D is converted to its active hormone form by the liver and the kidney. The calciferol is converted to 25-hydroxycholecalciferol, calcidiol (fig.3), and then metabolized by the kidney to several active forms including 1,25-dihydroxycholecalciferol, calcitriol (fig.4).The main function of vitamin D in the body is to maintain blood levels of calcium and phosophorus. Vitamin D is essential for the absorption of these substances from the small intestine, and also for the mineralization process of the bones. The result of vitamin D deficiency is rachitis (rickets) in children and osteomalacia in adults.
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Stability
As one of the fat soluble vitamins, vitamin D is stable in food storage, cooking and processing.Top
Synthesis
Cholecalciferol is manufactured by irradiating 7-dehydrocholesterol with ultraviolet light. The production of ergocalciferol is similar, using a starting product of ergosterol, a yeast extract.Top
Chemical Structure For Vitamin D
Source: http://www.chm.bris.ac.uk/webprojects2002/schnepp/vitamind.html
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