increase vitamin d An overwhelming number of Americans are deficient in vitamin D all year long. In fact, one Nutrition Research study put that number at 41.6 percent.

But, in the winter, our levels of the “sunshine vitamin” tend to drop even further, with scientists at the University of California–Davis stating that current recommended intake levels for vitamin D need to be increased by as much as 500 percent during the winter months in order to support healthy vitamin D levels.

That’s because the majority of our vitamin D is produced in the body in response to the absorption of UVB rays from sun. In the wintertime, the days are shorter than ever and, according to a review published in The American Journal of Clinical Nutrition, north of Atlanta, the sun’s rays become so indirect that our bodies cannot absorb as many UVB rays as they can in the summer months. What’s more, people with darker complexions as well as the elderly are less efficient at converting UVB rays into vitamin D, explains Shanna Levine, M.D., clinical instructor of medicine at the Icahn School of Medicine at Mount Sinai in New York.

Unfortunately, too-low levels of vitamin D are linked not only seasonal affective disorder (a more intense version of the “winter blues”), but also muscle and bone loss, as well as an increased risk of Type 2 diabetes (irrespective of weight) and cancer.

So if you haven’t had your vitamin D levels checked, now’s the time, Levine says. Your doctor can perform a simple blood test to determine your levels and if you need to increase vitamin D intake in the months ahead.

This Winter, Increase Vitamin D Levels

Here are four simple, expert-approved ways increase vitamin D levels – even during the cold, dark days of winter.

1. Eat Vitamin D Foods

Just because the majority of our vitamin D comes from sun exposure, that doesn’t mean food can’t help support healthy levels. Some foods, including pork, mushrooms and fatty fish, are naturally rich in vitamin D, Levine says. (A single serving of canned tuna contains about one-third of your recommended daily intake.) Plus, many foods – including dairy and eggs – are fortified with the essential nutrient. One 2016 study from the Cork Centre Center for Vitamin D and Nutrition Research found that eating just seven vitamin D–enriched eggs per week can protect against low vitamin D levels in the wintertime.

2. Get Outside

Don’t use the cold as a reason to hole up indoors all winter long. While at northern latitudes the ability to absorb UVB rays for the production of vitamin D is reduced, it’s not completely eliminated, says John Stracks, M.D., clinical assistant professor of family and community medicine at the Northwestern University Feinberg School of Medicine in Chicago. Schedule some outdoor time – like taking a walk during your lunch break, playing in the snow with your kids or going on a ski trip – whenever possible and, ideally, on slightly warmer days. Some exposed skin is required for your body to absorb the sun’s rays. Also, if you’ve been eager to visit the Caribbean or any other sunny destinations, the winter is the time to do it, Stracks says, noting that it can help give your D levels a needed boost.

3. Get a Vitamin D Lamp

Can’t get much natural light in your life? Try artificial light. Many light therapy boxes have been shown to have a protective effect against seasonal affective disorder. However, most do not actually increase vitamin D levels, Stracks explains. Currently, the only Food and Drug Administration-approved lamp on the market to raise vitamin D levels is the Sperti. It costs $425, but that’s cheaper than a cross-continental vacation and can be used every day.

4. Take a Vitamin D Supplement

When all else fails, vitamin D supplementation can help, Stracks says. It’s important to talk to your doctor before taking any supplements, as excessive intake should also be avoided. Your physician will be able to recommend a dose that will be most effective given your current levels – and make sure you get them where they need to be.

4 Ways to Keep Your Vitamin D Levels Up This Winter

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