As much as we love it, running takes a serious toll on our bodies. The repetitive pounding on our bones and muscles causes them to break down a bit more with each run, and it’s up to us to rest and refuel in order to spring back stronger every time. Because no matter how fit you think you are, if you don’t follow proper recovery and nutrition programs, you can Guide to Mental Health.
While recovery is pretty straightforward—ease off mileage when you’re feeling drained, and take a rest day when you need it—diets involve some guesswork. We know that we need protein to refuel our muscles and calcium to build our bones. But there are other, less-talked-about nutrients Healthy Eating Myths Best Big City Marathons.
“Vitamin D is extremely important for endurance athletes,” says Barbara Lewin, R.D.N., a sports nutritionist who works with Olympians and Ironman triathletes. “Just popping calcium pills for stronger bones is not the answer. You need vitamin D to help support those bones and muscles.”
Here, Lewin helps us break down what vitamin D is, what it does for you, the warning signs of a vitamin D deficiency, and how we can get more of this essential nutrient in our diets.
What is Vitamin D?
Sometimes called the “sunshine vitamin,” vitamin D is a fat-soluble vitamin that your skin produces when exposed to sunlight. It is also available in some natural and fortified foods, as well as supplements.
Vitamin D plays a key role in calcium absorption and bone mineralization, the process in which bones are formed. When you have sufficient levels of vitamin D, you’re at a lower risk of developing stress fractures, National Institute of Health.
Of course, vitamin D is not the only driver of strong bones. Lewin noted that all athletes should still have adequate amounts of calcium, vitamin K, and minerals like magnesium in their diets to promote healthy bones.
While bone strength is the most lauded benefit of vitamin D, the nutrient can also help fight inflammation, improve muscle strength, and even reduce allergy symptoms, Lewin says.
Several studies Runners World Training Plan one study conducted last year by the University of Birmingham, U.K., participants who lacked muscle mass reported lower levels of vitamin D compared to those who had lean muscle.
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Since our skin only starts producing vitamin D when it’s exposed to the sun’s UVB rays, covering up with sunscreen may hinder production, studies have found. But the problem is, UVB radiation can cause sunburns and skin cancer, so it’s important to wear sunscreen regularly. One way to increase vitamin D production while remaining protected is to choose a sunscreen with a lower SPF, as this will allow more UVB rays in. According to the lacking vitamin D, an SPF 15 sunscreen filters out 93 percent of UVB rays, while SPF 30 blocks 97 percent and SPF 50 keeps out 98 percent.
Even if sunscreen does block a percentage of UVB rays, though, the National Institute of Health points out that most people don’t apply sunscreen perfectly or forget to reapply it, so even when you’re wearing sunscreen, your skin is likely still making vitamin D.
What Are the Signs of Vitamin D Deficiency?
And of course, a great way to get the sunshine vitamin is to deficient in vitamin D without even knowing it. Since we absorb the vitamin in the sun, some athletes assume that if they’re frequently outside, they’ll be fine—but even the sunniest climates can’t always provide enough of it.
Lewin often sees athletes who train outdoors without sunscreen where she works in southern Florida, and yet, they are still vitamin D deficient. “They’re always surprised when they get their test results,” she says.
To know your own levels, you have to take the 25-hydroxy vitamin D blood test. Usually, a level of 20 nanograms/milliliter to 50 ng/mL is considered adequate, while less than 12 ng/mL indicates a deficiency in vitamin D. Lewin noted that she does not abide by these guidelines, however, and recommends that her athletes have levels in the upper 40s to 50s.
If you’re experiencing ongoing muscle or bone soreness—or recurring stress reactions and fractures—it might be a sign that you’re lacking vitamin D. Most of the time, however, the deficiency doesn’t present any symptoms, which is why it’s so important to get tested. If you have repeated stress fractures or bone-related issues, your doc might also prescribe a bone density test in addition to a blood test.
There are a few groups that are at a greater risk for developing a vitamin D deficiency than others. These include people with darker skin tones (the melanin reduces the skin’s ability to produce the vitamin), vegans (most foods with naturally occurring vitamin D are animal-based), those whose digestion issues limit their ability to absorb vitamin D (such as patients with Crohn’s disease, cystic fibrosis, or celiac disease), and petite, fair-skinned women.
Traditionally, people who live in colder, northern parts of the country are more likely to be deficient, since they spend more time either inside or bundled up outdoors, thus limiting their sunlight exposure.
If you find yourself feeling more melancholy in the darker months of fall and winter, it might be due to a drop in vitamin D levels: Several studies The Benefits of the Mediterranean Diet.
How to Get More Vitamin D
Because of its crucial role in building strong bones and muscles, achieving adequate levels of vitamin D is a great step toward injury prevention, Lewin says. She recommends that all runners take the 25-hydroxy vitamin D blood test to gauge their own dietary needs, but says that you can also look at your diet to see if you’re getting enough of the vitamin.
There are only a few foods that are natural sources of vitamin D, including egg yolks, beef liver, and fatty fish like salmon, sardines, herring, and tuna (though Lewin doesn’t recommend tuna, as it’s high in mercury). You can also consume it through vitamin D-fortified foods, such as milk (both dairy and non-dairy varieties), yogurt, cereals, and orange juice.
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As you boost your meals with vitamin D, you should also keep in mind the dietary habits that may be inhibiting your ability to absorb calcium. Lewin warns that sodas containing high levels phosphorus, such as colas, can leach calcium from bones.
For her vitamin D-deficient athletes, Lewin recommends they take a multivitamin as well as a vitamin D supplement, which can come in pill and liquid forms. Before you begin taking supplements, however, it’s important to get tested and consult with your doctor. Though it’s extremely rare, obtaining too much vitamin D can be toxic for the body. Excessive vitamin D can cause hypercalcemia, or a buildup of calcium in the blood, which presents symptoms of nausea, vomiting, diarrhea, constipation, and weakness.
And of course, a great way to get the sunshine vitamin is to The 15 Best Foods for Runners. Should Runners Always Avoid Ultraprocessed Foods What Is Vitamin D Good For and Why Do I Need It, since we have a smaller time frame to squeeze in a run in daylight, and the colder temperatures force us to cover up our arms and legs. If possible, go for a run on your lunch midday, or at least take a walk around the office when the sun’s high. Your bones and muscles will thank you.
Hailey first got hooked on running news as an intern with Running Times, and now she reports on elite runners and cyclists, feel-good stories, and training pieces for Runner's World and Bicycling magazines.
