Are You Smart About the Sun?

Confused about how to best manage sun exposure in order to get enough vitamin D without increasing your risk for skin cancer? Spending too much time in the sun has long been regarded as being bad for your health due to the increased number of cases of skin cancer. In fact, rates of skin cancer are increasing worldwide.1 That said, vitamin D deficiency has become a major health problem, especially for people over the age of fifty.2 So what is the best approach to spending time in the sun? To best answer this question, let's look at a few important factors involved in this dilemma.

Got Vitamin D?

Vitamin D is actually a hormone that plays an essential role in the body's absorption and use of calcium in order to grow, strengthen, and maintain healthy bones. It's also necessary for proper muscle function as well as for a healthy immune system. Recent research links cancer (breast, colorectal and prostate), heart disease, diabetes, and multiple sclerosis to low levels of vitamin D. While more research is needed to clarify the role of vitamin D in these diseases, vitamin d deficiency is increasingly being associated with other health problems like asthma, infections, and depression.

The sun is the most plentiful source of vitamin D. Certain fishes such as mackerel, salmon, and herring and in fish oils like cod liver oil are also rich in vitamin D. Since most of us don't get enough vitamin D in our diets, it's been added to products like milk, orange juice, yogurt, cheese, and bread. Even then, some of us still don't get enough vitamin D - making supplements an important part of maintaining our health. Here, moderation is important as excessive amounts of vitamin D are associated with health risks. The minimum recommended dose of vitamin D for adults is 800 IU, but many people may need more as sunscreens with SPF higher than 8 prevent absorption of vitamin D from the sun.

Aside from insufficient exposure to sunlight and poor diet, low levels of vitamin D occur as we age, gain too much weight (fat cells take up vitamin D), or take certain medications such as glucocorticoids or anti-seizure medications. Illnesses which impair our ability to absorb vitamin D from the gut, like Crohn's disease or celiac disease, can also lead to vitamin D deficiency. Genetic variants can also negatively impact your gut's absorption of vitamin D.

Got It Made in the Shade?

The threat that skin cancer poses to our health is real as 2 million Americans annually are diagnosed with skin cancer. That means there is no such thing as a healthy suntan or safe indoor-tanning and, as many of us have learned the hard way, you can get a sunburn on a cloudy day. So, yes, spending time in the shade is a good thing, but it's not the ultimate solution, especially with regard to vitamin D deficiency.

The American Academy of Dermatologists advises against sun exposure without the use of sunscreen or protective clothing. Others in the medical profession, however, recommend getting 10 - 20 minutes of sun (without sunscreen) on the arms, back or legs up to three times a week in order to get enough vitamin D. In the summer, you may need as little as 5 minutes of sun exposure to get sufficient amounts. Dr. Michael Holick of Boston University Medical Center, and author of The Vitamin D Solution, advises being sensible when in the sun.4 That includes wearing sunscreen on your face and hands even when getting your 10 - 20 minute dose of vitamin D three times a week.

The key to being sun smart is knowing where you stand with regard to your skin type, vitamin D, and the sun:

  • How quickly can you get a sunburn if you are outside without sunscreen?

  • What is your risk of getting skin cancer?

  • Could you be deficient in vitamin D?

It also means understanding how you can best protect yourself from sun damage and skin cancer. Here are several important tips to help you be smart about the sun:

  • Avoid excessive exposure to the sun. Remember, you can still get a sunburn or have sun damage by using sunblock too sparingly, too infrequently or incorrectly. In fact, you can still burn when you rely only on sunscreens to prevent skin cancer and sunburns are linked to cancer.

  • Use a sunscreen that blocks both UVA and UVB rays (broadspectrum), is water-resistant, and has an Sun Protection Factor (SPF) of at least 30. Check out the Environmental Working Groups list of good and bad sunscreens at:

  • Get a sunscreen with enough UVA protection. Many sunscreens sold in the U.S. would be not be approved to be sold in Europe because they fail to contain enough UVA protection.

  • Avoid sunscreens that contain these ingredients:

  • Oxybenzone: This hormone disruptor and allergen is still found in many sunscreens

  • Certain Form of Vitamin A: Retinyl Palmitate is a form of Vitamin A that causes skin lesions and tumors in animals.

  • Use sunscreen generously all over and don't forget your neck, ears, and feet.

  • Apply sunscreen 20 - 30 minutes before going outside.

  • Reapply every two hours and after swimming or excessive sweating.

  • If you play sports on a reflective surface (water, sand, concrete, snow), wearing a hat won't provide enough protection, so wear sunscreen, too.

  • Protect your eyes with sunglasses that block UVA and UVB rays.

  • The higher the elevation, the greater the risk of sun damage, so be sure to use sun protection.

  • Seek shade when possible and try to avoid spending too much time in the sun between 10 a.m. and 2 p.m.

  • Know what the UV Index is before spending time outdoors, that way you can protect your skin properly.

  • Avoid tanning beds.

  • Check your skin regularly for sun damage and see a dermatologist annually.5

Since many factors influence the risk of skin cancer and vitamin D deficiency, it's important to talk to your healthcare practitioner about your individual risks. Being safe in sun doesn't mean you can't have fun outdoors this summer, just be smart about it.


1 Grigalavicius, M et al. Abstract: Daily, seasonal, and latitudinal variations in solar ultraviolet A and B radiation in relation to vitamin D production and risk for skin cancer. International Journal of Dermatology 2016, 55, e23-28.

2 Scarlett, W. Ultraviolet Radiation: Sun exposure, tanning Beds, and vitamin D levels: What you need to know and how to decrease the risk of skin cancer. Journal of the American Osteopathy Association 2003 103 371-375.

3 Hansen, L., Tjonneland, A., Koster, B., Brot, C., Andersen, R., Lundqvist, M., Christensen, J., Olsen, A.. Sun exposure guidelines and Serum Vitamin D Status in Denmark: The Status D Study. Nutrients 2016 8 266.

4 Holick, M. The Vitamin D Solution: A Three Step Strategy to Cure Our Most Common Health Problems Hudson Street Press 2011.