Vitamin D from Safe Sunlight Exposure
Vitamin D is produced by light whose wavelength is between 290 and 300 nanometers. That’s part of the UV-B band, which ranges from 280 to 315 nanometers. (The total ultraviolet portion extends from 10 to 400 nm.)
This particular “color” (some birds and insects can actually see the color, but humans can’t) is included in natural sunlight, but is easily filtered out by dust, smoke, cloud, or even window glass.
Exposing most of your skin to strong, direct sunlight for about 10 minutes can produce about 10,000 IU of vitamin D3, if you skin is very fair. That’s about twice as much vitamin D as you need per day, on average. (If you are very dark-skinned you might take an hour or more to produce the same amount.)
Here are approximate sun exposure times for maximum daily vitamin D production for different skin types
- 10 mins – Very light skinned Caucasian
- 20 mins – Mediterranean
- 30 mins – Middle Eastern
- 40 mins – Southern Asian
- 60 mins – African (dark-skinned)
You may not find an exact match for your skin type in this list. Then see where you fit best, or slot yourself in between. For example, a medium skin tone Caucasian person might be 15 mins. The important thing to realize is that you stop making vitamin D soon after this time, even if you stay out in the sun for much longer. (You will be able to make vitamin D again the following day.)
Most of us might consider using the sun as a major source for vitamin D, at least for part of the year, but we are naturally concerned about skin damage, skin pigmentation, skin cancer, solar keratosis, sunburn, and let’s admit it, WRINKLES.
Now that vitamin D supplements are widely available, some people wonder whether it is not simpler and better to take the pills. (See below.) Personally, I think that sunlight is still the best option because it is the most natural.
For those of us who want to obtain safe sunlight exposure as part (or all) of their vitamin D strategy, we need to be very clear on exactly how to go about it, with complete safety.
How to Use Sunlight Safely
Vitamin D3 production is naturally finished long before you start to burn, no matter what color your skin. (Obviously, that happens a lot quicker if your skin colour is very light.)
A light-skinned blond would take about 5 minutes of near full-body exposure in strong sun to create a good daily dose of vitamin D3, around 5000 IU. Other skin types take longer.
- Avoid exposing areas of your skin which are already sun-damaged. If this makes it impractical to sunbathe, then rather take vitamin D3 supplements.
- Never allow yourself to burn, even slightly. Don’t even turn pink! It is not necessary.
Become familiar with your personal daily sunshine time limit. It should be less than the time it takes for you to notice any change in your skin colour, or any flushing. At the beginning of summer, before your skin has darkened from sun exposure, you will need to be particularly careful.
Experiment a little to find your limit. If you don’t know where to start, try 10 minutes of sun and make a careful note of any effects, such as skin flushing, which may happen immediately – or later. Your daily sunshine limit should be less than half the time it would take you to become the slightest bit sore.
Whenever possible, avoid exposure to your face and neck. (We all want to stay looking young, don’t we?) Sunscreen-on-your face will help protect it, and a wide-brimmed hat gives good protection. Or use both. Large-framed sunglasses help to protect the delicate area around the eyes. It is also a good idea to protect your hands.
The best protection of all is to move out of the sun altogether, once you have reached your limit for the day. Avoid relying on sunscreen alone for staying in the sun for long periods. Even if you don’t seem to burn, your skin can be damaged. Over the last 40 years, melanoma deaths have increased at about the same rate as sunscreen sales! Think about that.
Most people have already over-exposed their face, neck, hands and arms as children or young adults. These areas are usually first to show signs of sun damage. That is why you want to cover them, even while you expose the larger skin areas that have undamaged skin, for short periods only.
As you will be exposing more skin than usual, take particular care of the newly-exposed parts. They will be more sensitive because they are as yet untanned.
And if you are on holiday in a warmer climate than usual, start off with much shorter exposure times than you would use at home. Hotter sun burns quicker.
Finally, while taking sun, turn to expose a different part of your body every few minutes, Now that we have taken care of safety, let’s look at effectiveness.
Creating Your Own Vitamin D3
When you get the opportunity, try to expose as much skin as possible to direct sunlight, once a day. The more skin you expose, the more vitamin D you will make and the less time it will take. So your risk of damaging your skin is minimised.
At least four times a week of at least 40-50% body exposure is needed to get you into optimum vitamin D territory from sunlight alone. Older people may need more.
Don’t wear sunscreen all over while you are getting your vitamin D sunshine. An SPF 15 sunscreen absorbs 93% of the UV-B rays. What gets through isn’t nearly enough to make vitamin D.
Don’t sit behind glass. UV-B rays are 95% absorbed by ordinary window glass and 99% absorbed by your car windscreen. But most of the UV-A light still gets through, and that can damage your skin too.
Children also need sun exposure (with adult guidance) to build up healthy vitamin D levels.
Some Vitamin D3 is created inside your skin cells, so it can’t wash off. But more is created in the natural oil on top of your skin. This can be washed off, especially if you use soap, or hot water.
The longer the skin oil remains on the skin after sunning, the more vitamin D will be absorbed. Several hours are needed for total absorption. Your skin re-absorbs your skin oil – and the vitamin D with it.
Prepare your body for sun exposure by taking antioxidants. Fresh fruits and berries are great. A daily antioxidant supplement is a good idea too. And vitamin D itself protects your skin from radiation damage, which makes perfect sense.
For a high level of protection from UVB damage, there is a natural antioxidant herb with a special affinity for skin, called polypodium leucotomos. It’s a kind of fern. After taking a course of this antioxidant (as pills), you may find you can stay in the sun more than twice as long without burning. How this will affect vitamin D production is not known.
For most people, a daily fruit salad, with berries, will help to keep antioxidant levels well stocked.
Vitamin D3 – Needed All Year Round
Depending on where you live, you may be able to use sunlight as your primary source of vitamin D for several months of each year. This is the best way to get vitamin D during the warmer months – if this is practical for you.
For the rest of the year, don’t allow your vitamin D levels to dive. Best health is obtained by maintaining your 25(OH)D blood level at close to optimum, all year round.
So during the winter months, take a good-quality vitamin D3 supplement.
Advantages of Sunlight as a Source of Vitamin D
- You don’t have to remember to take a pill
- Sunlight costs nothing
- You cannot overdose on vitamin D from sun exposure alone
- There might be other undiscovered benefits to having sunshine on our skin, besides creating vitamin D.
Disadvantages of Sunlight as a Source of Vitamin D
- It is hard to know how much vitamin D you are getting
- If you stay in the sun too long your skin will burn
- The sun doesn’t always co-operate.