Research has found vitamin D supplements can improve mental sharpness, ward off colds and fevers, reduce your belly fat and more (check out the full list of benefits here). And a new study from the Society for Endocrinology annual conference in Edinburgh is adding two more positive health benefits: Daily intake of vitamin D supplements can increase your exercise performance and lower your risk of heart disease.
First, a quick lesson on vitamin D: It’s actually a vitamin and a hormone that helps moderate levels of calcium and phosphate in your blood—in addition to being essential for the formation and growth of healthy bones and teeth. It’s hard to get sufficient amounts of vitamin D from food sources like oily fish and eggs alone (you need about 400-600 International Units (IU)/day, according to the Mayo Clinic), and that’s where supplements come in. (Though you an also get D via the sun, baking in the sun for the sake of vitamins may not be the best strategy, and some parts of the country don't exactly make that super easy, regardless.)
Okay, back to the benefits. The researchers looked to previous studies that suggested vitamin D can block the action of enzyme 11-βHSD1, which produces the stress hormone cortisol. High levels of cortisol can potentially raise blood pressure by restricting arteries, narrowing blood vessels, and promoting your kidneys to retain water, according to a release about the study. So the researchers thought if vitamin D could reduce circulating levels of cortisol, it may also improve exercise performance and lower cardiovascular risk factors.
Two find out, researchers gave 13 healthy adults of the same age and weight (though they don’t state the specifics) 50μg of vitamin D per day or a placebo for two weeks. The results: Adults supplementing with vitamin D had lower blood pressure compared to those on the placebo; they also had lower levels of the stress hormone cortisol in their urine at the end of the two weeks.
Next, the researchers conducted a fitness test. They found the vitamin D group could cycle 6.5km (4 miles) in 20 minutes, compared to just 5km (3 miles) at the start of the experiment. That's an impressive 30 percent further. What's more: They also showed lower signs of physical exertion. In other words, they probably felt like they weren't working as hard.
If a supplement could make our next sweat session feel easier, we say it's worth a try. Talk to your doctor about exactly how much you should take before adding Vitamin D to your regimine.