For those of us in South Africa, we spend a lot of time in the sun. Regular sun exposure, without sunscreen, causes your skin to produce vitamin D naturally, which is good for you. But how much sun do you need?
You’ve probably seen some vague guidelines, recommending “a few minutes every day” but this is far too general to be useful. The amount of sun you need to meet your vitamin D requirements varies hugely, depending on your location, your skin type, the time of year, the time of day, and even the atmospheric conditions.
In our modern, sedentary, computer-fixated, office-based lifestyle we compromise our chances of getting sufficient sunlight. How many of us can get out of the office during the optimal 10am to 2pm timeslot? Remember too, that cloud cover reduces the sunlight and so does smog, pollution, certain clothes and of course moisturising creams containing UV protection.
Large amounts of vitamin D3 (cholecalciferol) are made in your skin when you expose all of your body to summer sun. This happens very quickly; around half the time it takes for your skin to turn pink and begin to burn. This could be just 15 minutes for a very fair-skinned person, yet a couple of hours or more for a darker-skinned person.
You don’t need to tan or to burn your skin in order to get the vitamin D you need. Exposing your skin for a short time will make all the vitamin D your body can produce in one day. In fact, your body can produce 10,000 to 25,000 IU of Vitamin D in just a little under the time it takes for your skin to turn pink. You make the most vitamin D when you expose a large area of your skin, such as your back, rather than a small area such as your face or arms.
When the sun’s rays enter the earth’s atmosphere at too much of an angle, the atmosphere blocks the UVB part of the rays, so your skin can’t produce vitamin D. This happens during the early and later parts of the day and during most of the day during the winter season. The closer to midday you expose your skin, the better this angle and the more vitamin D is produced. A good rule of thumb is if your shadow is longer than you are tall, you’re not making much vitamin D. In winter, you’ll notice that your shadow is longer than you for most of the day, while in summer, your shadow is much shorter for a good part of the middle of the day.
Having said all the above, whilst it is important to get your “daily dose” of Vitamin D, it is imperative to protect your skin using sunscreen when you know you are going to be outside a lot, if you are fair-skinned and burn easily and if you participate in sport.
Unsure of how to balance your Vitamin D intake with prevention against the harmful rays of the sun? Call me for a chat and let’s get together.