Sunshine Vitamin

Vitamin Ds role in skeletal growth and maintenance and in the formation of teeth and the bones is well-known. Severe deficiency of this vitamin leads to soft bones that bend and break easily referred to as rickets in children and osteomalacia in adults. But,there is much more to the sunshine vitamin when it comes to what it does for us.

In addition to maintaining calcium and phosphorus balance,vitamin D also maintains maximum muscle strength,inhibiting inflammatory activity and preventing diseases related to the immune system,including type I diabetes,multiple sclerosis,systemic lupus erythematosus (SLE),rheumatoid arthritis and many common cancers. Low levels of vitamin D have also been linked to hypertension,cardiovascular disease,type II diabetes mellitus,tuberculosis,asthma,psoriasis and depression. An exposure of half an hour a day,around mid-day (11 a.m. to 3 p.m.) is recommended for preventing deficiency. However,despite,abundant sunshine,Indians are particularly prone to vitamin D deficiency. Some of the reasons could be inadequate exposure to sunlight,particularly for those who remain indoors during the day or home bound elderly and an increased use of sunscreens,which is recommended for prevention of skin cancer. Research has also shown that Indian skin pigmentation needs several times more exposure to sunlight,as compared to fair-skinned,in order to generate the same amount of this vitamin. In general,the greater the skin pigmentation,the lesser vitamin D is produced. In India,vitamin D deficiency is more common among pregnant women,schoolchildren,young adults and the elderly. Vitamin D deficiency can occur without any symptoms but when symptoms occur,it indicates severe deficiency. Vigilance of ones vitamin D status by the yearly measurement of 25-hydroxyvitamin D,the storage form of this vitamin which correlates best with deficiency symptoms,should be included in annual health check-ups. In the body,vitamin D is converted into a hormone called calcitriol which helps regulate the immune system. Studies suggest a link between vitamin D and tuberculosis. In one study,one third of the total subjects suffering from tuberculosis were found to have vitamin D deficiency and supplementation with vitamin D significantly enhanced recovery. High intake of vitamin D by pregnant mothers reduces the risk of asthma by 40 per cent in children between 3 to 5 years old. Higher blood levels of vitamin D helps reduce the risk of type 2 diabetes by almost 40 per cent.

Most experts agree that the minimum daily intake of vitamin D should be at least 800-1000 I.U. per day to maintain a healthy concentration of 25 (OH) D in the blood. In India,where there are no policies for fortification of vitamin D,getting enough of this vitamin poses a challenge. If adequate sunshine exposure is not possible,supplements must be taken strictly under medical supervision as vitamin D can be toxic if taken in excess.