You may think that just because it’s summer, you don’t need to worry about your vitamin D levels. You’re wrong. Concerns over skin cancer, encouragement to avoid direct sunlight and increased use of sunscreen means we’re all at risk of vitamin D deficiency.
Every cell in your body has a receptor for vitamin D, which makes it more like a hormone than a vitamin. It supports a healthy immune system and is critical for people with autoimmune diseases. It’s necessary for your body to absorb calcium, and women with low levels of vitamin D are at a higher risk of osteoporosis. Don’t forget about mood – the winter blues are actually related to vitamin D deficiency.
Vitamin D is produced by sunshine. However, in the northern latitudes, the sun is only strong enough to stimulate vitamin D production in your skin 3 to 4 months a year, typically from May through August. During these months, your skin could make enough D to support good blood levels, if you are outside for at least 20 minutes a day, withoutsunscreen, typically between 11am and 1 pm, in shorts and a tank top. In other words: your arms and legs need to be fully exposed without sunscreen during peak hours of maximum sun to produce sufficient levels of vitamin D. For most people, that’s not likely to happen.
It’s hard to calculate exactly how much time you should spend in the sun to meet your specific vitamin D needs. The Vitamin D Council recommends that you stay in the sunlight for around half the time it takes for your skin to begin to burn. Moderation is key since overexposure can increase the risk of skin cancer. So, take some time on a sunny day to sweat it out, literally, outdoors before the clouds arrive and block that precious sunlight.
Here are some more tips on what you can do to help your skin produce more vitamin D in the summer sunlight:
- It is ideal to spend at least 20 minutes between 11 am and 1 pm in direct sunlight. During this period, the ultraviolet B (UVB) rays responsible for vitamin D formation are at their maximum wavelength. Make sure you keep yourself hydrated when out in the sun in peak summer months.
- Stand or walk directly under the sun, unshielded by a glass window, umbrella, tree or any other covering above. They block all UVB rays.
- Adjust your timing in the sun depending on the season of the year. According to the Vitamin D Council, a good rule of thumb is if your shadow is longer than you are tall, you’re not making much vitamin D. In the winter, you’ll notice that your shadow is longer than you for most of the day, while during the summer, your shadow is much shorter for a good part of the middle of the day.
- In terms of clothing, less is more. The more skin you expose (preferably a quarter of your body) the more vitamin D is produced. For instance, you can wear sleeveless clothes and shorts and leave your face uncovered.
- When you’re trying to absorb vitamin D, do not apply sunscreen on exposed skin since that inhibits a lot of vitamin D production. However, only do this for a short period of time.