Of all vitamins, D is the most debated. You need it for calcium absorption and to keep your bones and muscles strong, but the best way to get it is from deep sunshine – with full SPF protection. Given that we live in the skin cancer capital of the world, with one in four Australians having a vitamin D deficiency, it’s a pretty delicate conundrum.
“We need UV-B light to make vitamin D,” explains Professor Rebecca Mason from the University of Sydney, “but it damages the skin, particularly the DNA, which can cause skin cancer if it’s not repaired properly.”
Sunscreen blocks UV-B rays, which means it also blocks the production of Vitamin D, so avoiding the sun completely is no longer recommended.
“Around 2005, the medical and scientific communities realised that sun exposure has benefits as well as risks,” Prof Mason says.
“We know that vitamin D deficiency is associated with an increased risk of falls and fractures, and poorer outcomes during pregnancy. There is also evidence that vitamin D helps prevent infections and provides some protection against inflammation and some autoimmune diseases.”
A balanced approach for most Australians (those not at high risk of skin cancer) is to plan for short-term exposure to vitamin D, and the best time to do this is now.
“We need to increase our skin’s defenses and reduce our exposure to the sun when the sun is less intense,” Professor Mason said, adding that as well as the risk of skin cancer, overexposure to the sun is never a good idea. It warns that there is no.
“When your skin is exposed to sunlight for extended periods of time, the vitamin D that is produced begins to break down before it can be absorbed by your body.”
How much UV-B is enough? It depends on where you live, how exposed your skin is, and how much natural pigment your skin has (the darker your skin, the longer it takes to produce vitamin D).
“A good rule of thumb is that no matter where you are in Australia in summer, late spring and early autumn, you should be light to dark skinned and go out at least four times a week between mid-morning and mid-morning. “Just wearing the equivalent of shorts and a short-sleeved shirt in the afternoon and getting five to 10 minutes of sun exposure afterwards can keep your vitamin D at acceptable levels,” says Professor Mason.
“In the early morning and late afternoon, little, if any, vitamin D is produced. The main message to remember is that with sunlight, as with many other things, moderation is key.”
Although sunlight is the best source of this particular vitamin, it is still essential to expose yourself to the sun safely. Be wary of even small amounts of sun exposure if you have any of the following symptoms:
- very white skin
- redhead
- Freckles and moles
- History of melanoma
- You are taking medications that suppress your immune system.
