Exactly how to tell if you need more D…vitamin d, that is.
The Most Common Low Vitamin D Symptoms
About a third of the population is deficient in the sunshine vitamin. Low vitamin D symptoms are vital to watch for, as a lack of this micronutrient has been linked to everything from heart disease and cancer to the flu and osteoporosis, according to the Harvard T.H. Chan School of Public Health.
Keep an eye out for these low vitamin D symptoms, and see your doc and ask if you should test your vitamin D levels if you’re unsure. Your bones will thank you.
You're Suffering from Stress Fractures
This is the only true symptom of low vitamin D, says Adrian Gombart, Ph.D., an associate professor in the Linus Pauling Institute at Oregon State University at Corvallis who studies vitamin D extensively. Vitamin D helps the body absorb calcium (the building blocks of bones) from food.
“If you have less than 20 micrograms per milliliter of vitamin D in your blood, you don’t have enough D to transport calcium into your bones.” The result? Weaker bones, which can increase your risk of injury, including stress fractures. (On that note, here’s how one woman learned to appreciate her body after countless running injuries, including, yup, stress fractures.)
You Keep Getting Sick
A meta-analysis of 39 studies found that low vitamin D levels are linked to an increased risk of both upper and lower respiratory tract infections. Onto of that, people with low levels of vitamin D are more likely to develop pneumonia than those with higher levels, according to a meta-analysis in the journal Medicine. So if that cough keeps coming back and you can’t figure out why—you wash your hands thoroughly, get enough sleep, eat a balanced diet, and so on—it might be due to a vitamin D deficiency. Talk to your doc.
You're Moody
The vitamin regulates the conversion of the amino acid tryptophan into serotonin—you know, the neurotransmitter that regulates mood. So if you can't shake your sad feelings, know that those lows could be a sign of vitamin D deficiency.
You Live in a City
Low-light areas mean less exposure to vitamin D-producing sunlight (we’re looking at you, northerners). When studying residents in Buffalo, New York, nutrition researcher Peter Horvath of the University at Buffalo School of Public Health and Health Professions found that nearly 50 percent of people have insufficient amounts of vitamin D and 25 percent may have vitamin D deficiency (having less than 30 micrograms per milliliter in their blood).
Exercise Seems Harder
Vitamin D is needed for muscle fibers to develop and grow, which explains why a meta-analysis published in the Health & Fitness Journal suggests that a vitamin D deficiency may affect muscle function and fitness levels. (BTW, here’s how to build muscle the *right* way, even if you’re not struggling with low vitamin D symptoms.)
You're Wishy-Washy
By now you know about vitamin D’s role in creating the all-important serotonin, right? Well, the neurotransmitter doesn’t just affect your mood; it also influences other cognitive functions, like decision making and impulse control, according to a study published in FASEB Journal. If your resolve is all over the place, this could be a symptom of low vitamin D.
You Don't Get Enough Sun
First of all, sunscreen is not a bad thing. I repeat: sunscreen is not (!!) a bad thing. Buy it. Apply it. Reapply it. "But your body can't create vitamin D from sun exposure when you wear sunscreen," says Gombart. No need to choose between skin health and bone health: Gombart suggests talking to your doc about adding a supplement to your routine.
