Vitamin D is a fat-soluble vitamin, also called as ‘Sunshine Vitamin’ because it is synthesised in the body in the presence of sunlight. It has critical metabolic functions in the body as it is needed for the absorption of calcium and phosphorus and aids in the process of bone mineralisation. Evidence from newer research studies have shown that, vitamin D has a far wider role to play, not only in musculoskeletal health, but also for preventing chronic diseases. Although more research is needed to determine the beneficial effects of vitamin D in these areas.
Studies have shown that vitamin D helps reduce the risk of developing diabetes, cardiovascular disease, certain types of cancers, depression, autoimmune disorders, allergy, infectious diseases such as tuberculosis, asthma, and even frailty.
Deficiency of vitamin D in all age groups over the world, has caught the attention of the medical fraternity recognising it as a pandemic with a myriad of health consequences. It has been estimated that around one billion people all over the world have inadequate levels of vitamin D in their blood.
Inadequate exposure to the sun on account of long working hours indoors during the day, travel by vehicles instead of walking, the use of sunscreens and not consuming enough of vitamin D rich foods are some of the factors that are contributing to such deficiency.
African, African-Caribbean and South Asian origin people, who have darker skin are at an increased risk of being deficient in vitamin D because melanin acts as a filter to ultraviolet B (UVB) radiation and reduces the amount of vitamin D that the body makes in the skin.
Deficiency of the sunshine vitamin in milder forms, leads to body aches, back ache and joint pain that does not respond to treatment. Severe deficiency leads to rickets (softening and weakening of bones) in children and osteomalacia in adults. Studies have shown that vitamin D deficiency may have a role in causing osteoporosis in older people.
The best way to know a person’s Vitamin D status is to have a yearly ‘25 hydroxy Vitamin D-3 test’ done. Since this is the storage form of vitamin D it correlates best with deficiency symptoms.
Requirements of Vitamin D are primarily met from the synthesis of vitamin D in the skin in the presence of sunlight. Very few foods naturally contain vitamin D. Ideally a balanced diet coupled with adequate exposure to sunlight should prevent vitamin D deficiency.
Ideal time for exposure to the sun: Reputed health authorities suggest that exposure to the mid-day sun from 10 a.m. to 2 p.m. is ideal for the production of vitamin D in the body as the UVB radiation is highest during this period. However, because of risk of extreme heat, sun burn and dehydration during this time especially during summer, it is recommended that one gets exposure to the sun just after sunrise from 8 a.m. to 10 a.m.
Those individuals who do not get adequate exposure to the sun should consider taking supplements of vitamin D in consultation with a doctor.
(The writer is a consultant nutritionist with 27 years of experience.)
