Walk through the vitamin aisle of any drug store and you’ll likely see a pretty hefty stock of vitamin D supplements. There’s a good reason for this: According to an article published in the Journal of Pharmacology & Pharmacotherapeutics, almost 50 percent of the population worldwide is deficient in vitamin D — which is cause for concern, given that vitamin D is a key factor in bone health. “Vitamin D is essential because it helps the absorption of calcium in our bodies,” nutritionist Keri Gans tells Allure. And, as the Cleveland Clinic reports, vitamin D also serves to block the release of a hormone that can lead to brittle bones.
In other words, vitamin D is important, and many people aren’t getting enough. To find out if you might be one of them, read on for what you need to know about vitamin D deficiency and to see if taking a supplement could boost your health.
Who might benefit from taking vitamin D?
“Postmenopausal women, women on long-term steroids, [and] expectant or breastfeeding moms have…increased needs in calcium intake for keeping their bones strong,” Gans says. “Also, in regards to prenatal health, it is important for the development of healthy bones in the fetus.”
A deficiency is also more common in people with dark skin than light, because the increased amounts of melanin serve as a natural barrier to the UV rays. Similarly, people who regularly wear sunscreen with an SPF of 30 or higher may have reduced vitamin D levels. (This doesn’t mean you get to skip daily sunscreen application — getting sufficient vitamin D shouldn’t mean putting yourself at risk for skin damage.)
Weight and diet play a role here, too. People who are obese may also benefit from supplementing their diets with vitamin D to achieve optimal levels, and people with vegan diets may need to do the same: “A person who follows a strict vegan diet might be at a slightly higher risk, since they may not consume as many calcium-rich foods,” Gans says.
Is taking vitamin D more important in the winter?
It can be, Gans says. The most commonly known cause of vitamin D deficiency is lack of exposure sunlight. According to Mayo Clinic, few foods contain the vitamin. (According to the National Institutes of Health, the best food sources of vitamin D are fatty fish like salmon, tuna, and mackerel.)
This means that for most people, the big fireball in the sky is a critical source of the stuff. Unsurprisingly, vitamin D levels can take a dive during the winter, when sunlight is oh-so-scarce. “For some people, they get their daily vitamin D from sunlight,” Gans says. “And depending on where they live, the position of the sun in the winter doesn’t yield strong enough ultraviolet B rays to penetrate the atmosphere.”
What benefits could taking vitamin D have beyond bone health?
Your bones might not be the only part of your body benefiting from increased levels. There is some evidence that suggests a connection between vitamin D levels and mood, as well as some research that points to an association between vitamin D deficiency and depressive symptoms.
Though the current research on the topic is limited and inconclusive and vitamin D supplements certainly aren’t guaranteed to boost your mood, they don’t come with many risks — as long as you stick with the recommended dosage, which is measured in international units (IU) and is indicated right on the front of supplement bottles.
So how much vitamin D should I consider taking?
“There is potentially no harm in taking the recommended dosage of 600 IU daily,” Gans says, citing the Institute of Medicine’s recommendation for healthy individuals. “But to really benefit from the supplement, it would warrant being tested to find out if a deficiency is present.” If you want to check your vitamin D levels, make an appointment with your doctor, who can order a blood test to determine where you stand. If you are deficient, Gans says, your doctor may recommend a supplement with a higher dosage.
Just be sure not to take more than 10,000 IU per day. “Since vitamin D is a fat-soluble vitamin, too high a dosage can result in harmful side effects such as fatigue, loss of appetite, dehydration, vomiting, confusion, and high blood pressure,” Gans warns. Again, as with any supplement, if you’re unsure about exactly how much you should be taking, it’s never a bad idea to check with your doctor. It’s probably also not a bad idea to book a vacation to a sunnier climate.
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