VITAMIN D

What May Be The Benefit Of Giving Supplements Of Vitamin D To The Elderly?

What May Be The Benefit Of Giving Supplements Of Vitamin D To The Elderly?

Introduction

Vitamin D is a fat soluble vitamin needed by the human body for maintaining and promoting the body functions. It is contained in food, added to some food and available as a dietary supplement. It is also obtained when one exposes itself to sunlight. Vitamin D is biologically inert; it undergoes a hydroxylation in two stages in the body for its activation. The first occurs in the liver, it converts vitamin D to 25 hydroxyvitamin D (25(OH)D) also called Calcidiol while the second form takes place in the kidney primarily by forming active 1, 25-hydroxyvitamin D (1, 25(OH)2D) also called Calcitriol (Van de berg, 1997). Vitamin D promotes absorption of calcium which is stored in the body as fatty tissue while Calcium is effective in the functioning of normal bone mineralization and prevention of hypercalcemia. Without enough vitamin D, the bones become so weak and thin, causing certain bone diseases but when it is enough it prevents rickets in children and osteomalacia in the elderly (De luca, 2004). According to the institute of medicine, specific recommendation for dietary intake or supplements are required for people over the age of 65 years, and those living where there is little exposure to sunlight because they are at risk of deficiency of vitamin D. Vitamin D requirement for 51-65 years is 400IU/d or 10ug/day, while 65years plus require 15ug/day or 600IU/d (FAO/WHO, 2001). Vitamin D deficiency is associated with some diseases such as rickets in children, osteoporosis in the elderly and other diseases which I have discussed. Supplementation may be a reasonable way to meet the recommended level of vitamin D required by the body since it has a positive effect on reducing bone diseases in the elderly.

Vitamin D

The name vitamin D was originally given to a crude product of irradiation of ergosterol which had a mixture of isomers of ergosterol. When it was discovered to be an active compound, it was called vitamin D2 or ergocalciferol .Another was found as a compound formed in the skin it was called vitamin D3 or cholecalciferol. Ergocalciferol is used for enrichment and fortification of food, its metabolic fate is the same as that of the dietary cholecalciferol (Lips, 2006) .D2 and D3 are the two types which are most important for plants and humans, collectively they are called calciferol. Vitamin D2 is gotten from plants in response to ultraviolet radiation which in turn damages protein, DNA and RNA. It serves as a screening device that protects organisms from the damaging high energy ultra violet radiation (Holick, 2004).Vitamin D3 are also known as cholecalciferol which are made from 7-dehydrocholesterol in the skin when exposed to sunlight. Vitamin D when stored in the liver, they are absorbed and converted to calcidiol or 25, hydroxyvitamin D[25(OH)D] which is the main circulating form of the ...