Healthy Living One Change at a Time

One Change at a Time: Vitamin D and Sunlight

Vitamin D was one of the vitamins my mom was always concerned about us getting enough of when we were kids, probably because most of my childhood was spent in the rainy Pacific Northwest. I remember having a glass of milk with every meal because “you need your vitamin D.” My grandpa was also a big vitamin D advocate. He swore his “pearlies” (the Vitamin D capsules he took every day) were the secret to good health. For a long time, I thought that belief was probably more placebo effect than fact, but the more we learn about vitamin D and its role in our health, my mom and my grandpa’s faith in vitamin D may not have been that far off. There is an increasing body of evidence indicating that low vitamin D levels increase the risk of colon cancer. The risk of other types of cancer and heart disease may also be linked to low vitamin D. Vitamin D also supports the immune system, strengthens bones and muscles, improves glucose metabolism, and reduces inflammation. It lowers the risk of multiple sclerosis, diabetes, and rickets. It can help lower blood pressure, improve sleep quality, and boost mood. The more we learn about vitamin D, the more we understand that it’s a key component in maintaining good health.

Unlike most vitamins, however, vitamin D is not something that we easily gain through food. Vitamin D is found in very few foods. Egg yolk, fortified milk and yogurt, liver, mushrooms that have been exposed to UV light, and sardines are among the few sources of dietary vitamin D. Fortunately, vitamin D is something we can make on our own with exposure to sunlight. That’s why vitamin D is often called the “Sunshine Vitamin.”

All this brings me to two questions: How much vitamin D do you need? How much can you get from the sun? Unfortunately, the answer to those questions has a lot to do with you as an individual. The recommended daily allowance for vitamin D on food labels is 400–800 international units (IU). This morning, I looked at the label on my cup of yogurt, and it gave only 2% of that daily recommended amount, which to me just emphasized that food is not the answer to increasing vitamin D. That leaves two options for getting vitamin D: sun exposure and vitamin D supplements.

The amount of sun exposure time you need to make adequate amounts of vitamin D depends on several factors, including the time of day, the season, your geographical latitude and altitude, your skin color, your age, weather conditions, and air pollution. For instance, in the spring and summer, nearly everyone in the U.S. can get adequate sun exposure to boost their vitamin D levels. But in the winter months, anyone north of the 37th parallel north latitude will have a hard time getting enough vitamin D from the sun (the 37th parallel north latitude is a line that runs centrally across the U.S., just south of San Francisco, Denver, St. Louis, and Richmond, VA). This happens because of the amount of UV that makes its way through the atmosphere at that time of year. Fortunately, we can store vitamin D in our fat cells to help balance out many of those variables. Some experts recommend “sensible sun exposure” in order to get enough vitamin D from the sun. The first rule with this method is to never, ever get a sunburn. Sensible sun exposure means always protecting your face and the tops of your ears and allowing 10-15 minutes of unprotected sun exposure to your arms, legs, abdomen, and back regularly between 10 a.m. and 3 p.m.

But regular sun exposure carries its own risks. The American Cancer Society does not support sun exposure as a way to increase vitamin D because sun exposure also increases the risk of skin cancer. Overexposure to the sun and the use of tanning beds are the most significant risk factors for melanoma, the deadliest type of skin cancer. One sunburn every two years triples a person’s risk for melanoma.

Because vitamin D is much needed and sun exposure is complicated and can carry its own risks, the best option is to discuss vitamin D with your primary health care provider. They can test your vitamin D level and then decide on the best plan for you to maintain a good vitamin D level based on your individual needs. With how important vitamin D is to overall health, making sure you have good levels of vitamin D is one of those “one change at a time” things you can do to get and stay healthier.


Carol Cates

By: Carol A. Cates, MSN, MBA, RN
Chief Nursing Officer
Odessa Regional Medical Center

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