Are you getting enough vitamin D?
A clinical review in the Journal of the American Osteopathic Association shows that nearly 1 billion people around the world aren’t, and it may be due to chronic disease or lack of exposure to the sun.
“People are spending less time outside and, when they do go out, they’re typically wearing sunscreen, which essentially nullifies the body’s ability to produce vitamin D,” Kim Pfotenhauer, DO, assistant professor at Touro University, and a researcher on the study, said in a press release.
“While we want people to protect themselves against skin cancer, there are healthy, moderate levels of unprotected sun exposure that can be very helpful in boosting vitamin D.”
Overdoing it on sunscreen?
Vitamin D is made by the body when skin is exposed to sunlight.
It can also be found in foods such as fish and eggs.
A deficiency in vitamin D can cause brittle bones and weak muscles.
“Studies continuously show that we are amid a vitamin D deficiency pandemic,” Amber Tovey, program manager at the Vitamin D Council, told Healthline.
She believes a hypercautious approach to sun safety could be to blame.
“Sunscreen plays a large role in the vitamin D deficiency pandemic,” Tovey said. “Due to the danger of skin cancer many people are afraid of the sun, and they use sunscreen any moment they go outside, neglecting their bodies of the readily available natural vitamin D from the sun,”
But Tovey emphasizes people should still be sensible about sun exposure.
“This does not mean that skin cancer is not a real threat to one’s health. One should take the proper precautions to not receive excessive amounts of sun exposure. It’s all about moderation,” she said.
So is it possible to get adequate levels of vitamin D while still avoiding skin cancer?
In an article for the Skin Cancer Foundation website, Dr. Anne Marie McNeill, PhD, and Erin Wesner, debunk the myth that using sunscreen will lead to a deficiency in vitamin D.
“The problem is, too many people think that using sunscreen and other forms of sun protection leads to vitamin D deficiency, and that the best way to obtain enough of the vitamin is through unprotected sun exposure. But that can lead to a whole other set of serious problems,” they wrote.
“When you add up the pros and cons, letting the sun beat down on your face and body is not the way to satisfy your D quotient,” the article authors added.
Simply put, UVB radiation from the sun is both the best source of vitamin D and the major cause of skin cancer.
Sunscreens with a high SPF filter out the wavelengths that cause the production of vitamin D in the skin.
But no clinical study has ever found that everyday sunscreen use leads to vitamin D deficiency or insufficiency.
“One of the explanations for this may be that 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,” McNeill wrote.
A sunburnt country
Australia, a country known for its sunshine and beaches, is often referred to as the skin cancer capital of the world.
Approximately 2 in 3 Australians will be diagnosed with skin cancer by the time they are 70 years of age.
More than 750,000 people are treated for one or more nonmelanoma skin cancers every year.
Despite this, vitamin D deficiency is still present.
A recent national health survey found that just under 1 in 4 Australians (23 percent) were vitamin D deficient, though this varied widely by location and season.
“What was particularly interesting about this recent survey was that the highest rate of vitamin D deficiency was in the 18 to 34-year age range. This contrasts with our data from 1999-2000 where the highest rates of deficiency were seen in older adults,” Robin Daly, PhD, chair of exercise and aging within the Centre for Physical Activity and Nutrition Research at Deakin University in Melbourne, told Healthline.
Daly says one reason for this change in results was the finding that the highest proportion of people taking vitamin D supplements were in the older age group.
However, another factor was the habits of young adults.
“It was a little alarming that one-third [31 percent] of young adults were deficient — perhaps because many are working long hours and so obviously getting insufficient sun exposure, the main source of vitamin D,” he said.
In 1981, Australia’s Cancer Council launched the Slip, Slop, Slap campaign, to encourage the public to slip on a shirt, slop on sunscreen, and slap on a hat.
The campaign quickly became core to sun-safe practices in the country and is credited for playing a key role in a noticeable shift in public attitudes to sun safety.
Tovey believes that Australia’s rates of vitamin D deficiency could be in part due to the campaign, which she believes may have caused some in Australia to fear the sun.
“I believe this [vitamin D deficiency in Australia] is likely a result of heliophobia, which was encouraged by the Slip, Slop, Slap campaign,” she said. “Slipping on long-sleeved clothing, slopping on sunscreen, and slapping on a hat … All of these methods do block the sun, but in doing so, also block the synthesis of vitamin D.”
Dr. Rebecca Mason, PhD, is the head of physiology at the University of Sydney and has experience in the study of vitamin D. She says the Slip, Slop, Slap campaign is essential in the tropical and subtropical climate of Australia.
“The sun safety campaigns may contribute to some people avoiding the sun or too much sun, but are entirely necessary in Australia, correctly described as the skin cancer capital of the world, where we have people with mostly Caucasian or whitish skin in a tropical and subtropical climate. Somewhat surprisingly, though, there is not much evidence, in practice, that the use of sunscreens makes much difference to vitamin D status,” she told Healthline.
“Surprisingly, when vitamin D levels are measured in groups of people, often the people who say they wear sunscreen a fair bit have higher vitamin D levels. This is completely accounted for when you also factor in their sun exposure, which is usually much higher than the rest of the group,” she said.
Easy ways to obtain vitamin D
Those who are most at risk for vitamin D deficiency include older adults and people with disabilities, along with people who are housebound, have dark skin, have a chronic disease like multiple sclerosis, are obese, and those who work night shifts or are in enclosed environments like offices.
For most people, adequate vitamin D levels can be reached through regular, short intervals of exposure to sunlight.
McNeill and Wesner write that if done correctly, getting vitamin D from the sun should come easily and without the risk of skin cancer.
“The truth is, it doesn’t take much sun exposure for the body to produce vitamin D. Even committed proponents of unprotected sun exposure recommend no more than 10 to 15 minutes of exposure to arms, legs, abdomen, and back, two to three times per week, followed by good sun protection,” they wrote.
“That minor amount of exposure produces all the vitamin D your body can muster. After that, your body automatically starts to dispose of vitamin D to avoid an overload of the vitamin, at which point your sun exposure is giving you nothing but sun damage without any of the presumed benefit.”