About the Health Information

“So, my own skin produces vitamin D from sunlight? Then, why should I buy the supplements?” This is the most common question encountered by most of my orthopaedic colleagues.

Vitamin D metabolism, as shown in the picture, isn’t that simple. It needs adequate 7-Dehydrocholesterol under the skin, adequate quantity of sunlight, enough time for the sun to convert UV-B type of radiation into active vitamin D – as it is a fat soluble vitamin, it will need fat to absorb from the gut, healthy liver and kidney to convert. So, if all these are in the right proportion, you can probably survive the vitamin D scare.

UV-B radiation is highest between 10 am and 4 pm, as the sunlight is more vertical than tangential at this time of the day. As Indians, we generally have darker skin tone compared to the Western population, so high melanin content in our skin acts as a natural sunscreen. So, 45 minutes of direct sunlight on bare arms, legs, face and neck is essential to meet the required daily allowance of vitamin D.

With the exception of those who necessarily need to work outdoors in the sun, most Indians do not get adequate sunlight to produce vitamin D endogenously. But our cultural taboo to cover most part of our skin with clothing and the undying desire of most of our population to become fair with the use of sunscreen has also led to the ill fate of our body’s factory to synthesise vitamin D.

Not to mention the urbanisation of population, living in overcrowded tenement and high storied buildings without direct exposure to sunlight, pollution in the atmosphere, lack of outdoor activity, avoiding sunlight on sunny summers due to the discomfort of scorching heat have all led to the deficiency epidemic.

Therefore, in the Indian scenario, vitamin D sufficiency cannot be achieved by entirely depending on sunlight.

The author is an Associate Consultant in the Department of Orthopaedics at MGM Healthcare.

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