the sunny on vitamin D: should we get sun exposure?
Get it? I was super proud of that pun!
Here in the United States, summer has arrived! After what seemed like a very long (but relatively mild) winter, it’s finally warm and sunny. This year, I’ve vowed to go outside daily and enjoy the weather. It seems like the warmer seasons go by quickly, and I spend my winters yearning for the sun, only to spend too much time indoors when it finally comes out. Go figure.
Part of my commitment to going outside regularly is the fact that I want to raise my vitamin D levels, which have been chronically low for most of my life. Human skin makes vitamin D when exposed to midday sunlight, and many of us are deficient because we likely aren’t going outside enough or supplementing. Previously, I wrote an article about what supplements to take on a plant-based diet, which includes vitamin D for those who aren’t achieving adequate levels from sunlight alone. In this piece, I wanted to illuminate why it’s important to get safe sun exposure. We slather on sunscreen in fear of skin cancer, but in my opinion, it’s important (and doable) to regularly get sunlight on our skin while protecting ourselves from sunburns, which are dangerous.
Why is vitamin D important? Vitamin D is a hormone that promotes calcium absorption in the gut, critical for maintaining healthy bones. There’s evidence that vitamin D also regulates cell growth, immune function, and inflammation. As it has a multitude of functions in the body, it’s easy to see why a deficiency can be dangerous.
The debate around sun exposure centers on the fact that UV rays found in sunlight are considered a complete carcinogen, meaning that they can initiate cancer and promote its progression and spread. On this basis, some authorities, such as the World Health Organization and the American Cancer Society recommend total sun protection (clothes, hats, and sunscreen) during midday. However, non-burning sun exposure is linked to reduced risk of melanoma, the deadliest skin cancer.
Furthermore, a meeting of international experts convened by the National Academy of Sciences in 2016 (published in JAMA Dermatology) concluded, “although the harms associated with overexposure outweigh the benefits, the beneficial effects of UVR [ultraviolet radiation] exposure should not be ignored in developing new sun safety guidelines.” An observational study of 20,000 Swedish women published in the Journal of Internal Medicine found that sun exposure avoidance was a risk factor for all-cause mortality. Sun exposure has also been shown to lower blood pressure, protecting against heart attack and stroke, which are two of the top ten causes of death in America. A 2018 publication in the International Journal of Environmental Research and Public Health concluded that non-burning UV exposure “is a health benefit and should be recommended as such,” as low vitamin D levels are associated with increased risk of colorectal cancer, breast cancer, type 2 diabetes, and Alzheimer’s disease. Especially important to note is that regular, safe sun exposure increases skin pigmentation and thickening - retaining the benefits of and boosting protection from UV rays. So the more sun exposure you get over time, the more protected you get from its harmful effects.
There’s no question that sunburns caused by too much sun exposure are dangerous, so it’s critical to avoid them. But the reality is that a blanket recommendation to avoid the sun at all costs is misleading. It’s certainly doable to expose your skin to the sun, then cover up before getting a burn. Also, the amount of sun exposure necessary for vitamin D production or to cause a sunburn varies depending on individual genetics and skin pigmentation. For example, those with very pale skin may need just a few minutes of sun exposure for sufficient vitamin D production, while dark-skinned people could require many times as much.
are vitamin d supplements a good substitute for sunlight?
Though vitamin D supplements boost your vitamin D levels, the benefits of sun exposure go beyond raising vitamin D levels, as discussed above. One disadvantage of using vitamin D supplements in lieu of getting sun exposure is the potential for overdose. While your body regulates its natural vitamin D production, taking too many supplements can result in toxic levels. This is why it’s important to take supplements only as needed in response to a known (not self-diagnosed!) deficiency.
It’s also unclear just how effective vitamin D supplementation really is. Consider vitamin D and bone health. One 2014 meta-analysis investigating the benefits of vitamin D supplementation for bone health in adults reported mixed findings and concluded that “continuing widespread use of vitamin D for osteoporosis prevention in community-dwelling adults without specific risk factors for vitamin D deficiency seems to be inappropriate.” Another meta-analysis on supplementation in children found that supplements likely aren’t beneficial for those with normal vitamin D levels, though they may be useful in kids with a deficiency.
Finally, there’s a growing appreciation for the benefits of sun exposure and vitamin D outside of just bone health - notably, ecologic studies have shown lower rates of cardiovascular disease and other chronic diseases in areas with more sun exposure than regions with less sun exposure. However, one of the largest and most rigorous trials ever found that vitamin D supplementation had no impact on prevention of cancer, vitamin D, and stroke, though there is some evidence that vitamin D supplementation may reduce cancer mortality in cancer patients.
how to get sun exposure safely
If you have a family history of skin cancer, or any precancerous skin lesions, I recommend talking to your healthcare provider about the benefits and risks of getting sun exposure before implementing a routine.
To get adequate sun exposure for vitamin D synthesis, go out into the sun daily between 10AM-4PM, and expose as much skin as you can without sunscreen or clothes.
Depending on your skin color, limit your exposure. The paler your skin is, the less sunlight you’ll need. Rule of thumb: don’t get burned, and be careful! If your skin begins getting dry/irritated/red, immediately cover up or apply sunscreen.
Be careful not to get too much sun, too fast. In other words, if you’ve been sitting in an office all year and haven’t gotten sun exposure, don’t spend an entire day unprotected on a sunny beach. Remember: sun exposure over time is protective, and sunburns are dangerous.
The sun does cause your skin to age, so if you’re concerned, wear a hat to prevent wrinkles from forming on the sensitive skin of your face.
sun exposure tips for Muslim women
As a Muslim woman who covers, it’s more challenging to get sufficient sun exposure. This isn’t for lack of being outside: I completed my first marathon in November 2018, and spent sixteen weeks grinding out training runs. I have been chronically deficient in vitamin D for most of my life owing to the fact that most of my skin is covered when I go outside. It’s especially important for Muslim women who cover to be aware of the importance of getting sun exposure, and take special measures to make sure they do for the health reasons discussed above. Furthermore, women who wear the headscarf often report hair loss, which could potentially be caused by vitamin D deficiency.
Find a private place to go outside. If you have a backyard, porch, or balcony, make a dedicated effort to get consistent, daily sun exposure. If not, ask to utilize a loved one’s private space.
If you have no access to a private space, go outdoors and expose a comfortable amount of skin to the sun. I spend at least half an hour outside daily wearing a turban, with my sleeves rolled up, and my hands and feet exposed. Though this isn’t ideal, it’s a compromise I’m personally comfortable with.
If you’re uncomfortable with exposing any skin in a public space, open a window indoors and sit in the sunlight with skin exposed. Make sure the sun isn’t passing through a medium! Glass windows block the UVB rays that stimulate vitamin D production, so sunlight through a window isn’t as beneficial.
This summer, I’ve spent more time taking long walks, getting fresh air, and enjoying the weather. Though getting enough sun exposure has been one of my goals, I’m gaining a lot more than I anticipated by making a concerted effort to go outside. I feel happier and more energetic. I feel in awe of nature and appreciate other living beings. Though I can’t point to a study, I imagine these feelings and experiences have made me healthier. Remember to zoom out as you pursue better health and stay conscious of the “why.” The end goal isn’t to achieve optimal levels of a certain vitamin. It’s about becoming your healthiest and feeling your best, so that you are free to pursue self-actualization and fulfillment. Getting some sun is a small step to doing so.