Dubai: While it is indisputable that sunshine can help our bodies manufacture Vitamin D, the fact is with the parallel emphasis on staying out of the sun due to fears of skin problems, it is often not clear to the public about how they must arrive at safe sun exposure. We ask Dr. Hala Mohamed,
Dermatology Specialist, Medcare Women & Children Hospital, to throw light on how to benefit from an essential, and safe, sun soak and how to protect the body from the damaging effects of the sun.
Role of the sunshine vitamin
When we speak about Vitamin D, we find it plays many roles in our body, with the most vital being regulating the absorption of calcium and phosphorus, and facilitating normal immune system function. Getting a sufficient amount of vitamin D is important for normal growth and development of bones and teeth, as well as improved resistance against certain diseases. Two main ways of getting Vitamin D are by exposing our bare skin to sunlight and by taking Vitamin D supplements.
Today, many people live the indoors lifestyle, far more than compared to previous generations. So it is recommended that everyone take 10 microgram supplementation of Vitamin D daily.
How is vitamin D manufactured in our bodies and what is the role of sun?
Exposure to the sun’s ultraviolet (UV) rays is required for vitamin D3 (cholecalciferol) to be produced. Vitamin D3 is synthesised in the skin once your unprotected skin receives exposure to sunlight UV rays. When ultraviolet rays from sunlight penetrate the skin, they react with 7-dehydrocholesterol which is a precursor to cholesterol. This reaction forms vitamin D3 (cholecalcifero) in the skin. It is then quickly converted by the liver to the prehormone 25(OH)D and then further converted in the kidneys to the hormone 1.25(OH)D2 which is the active form of vitamin D
How much sunshine is healthy?
More sunshine is essential, but not just at any time in the day. Fifteen to 20 minutes every day of early sunshine dawn till noon is crucial for your physical well-being: for your bones to remain healthy. Direct sunlight to your face. arms, hands and back for a short while (15-20 minutes) three to four days a week, is ideal.
10 to 15 minutes for a fair-skinned person.
20-30 minutes for a dark-skinned person.
What about fears of sun exposure?
Considering the increasing temperature in the emirates, it would be safe to soak in the sun between dawn and noon. Sunscreens are designed to filter out most of the sun’s UVB radiation, since UVB damage is the major cause of sunburn and can lead to skin cancers. UVB wavelengths happen to be the wavelengths that trigger vitamin D production in the skin.
Nonetheless, clinical studies have never found that everyday sunscreen use leads to vitamin D insufficiency. In fact, the prevailing studies show that people who use sunscreen daily can maintain their vitamin levels.
How much sunscreen should one use?
No matter how much sunscreen you use or how high the SPF, some of the sun’s UV rays reach your skin. An SPF 15 sunscreen filters out 93 per cent of UVB rays, SPF 30 keeps out 97 per cent, and SPF 50 filters out 98 per cent. This leaves anywhere from 2 to 7 per cent of solar UVB reaching your skin, even with high-SPF sunscreens. And that’s if you use them perfectly. So we can encourage people to soak in the sun but after informing them about its benefits and suitable times of the day to do that.
