At least 40 percent of adults in the United States are estimated to be vitamin D deficient. Even more may be at risk of vitamin D deficiency during the winter months, due to shorter days and less sunlight in northern climates.
Known as the “sunshine vitamin,” our skin produces vitamin D when exposed to sunlight. We also get it from food. It is an essential nutrient for strong bones, as many of us know. Your body needs D to properly absorb calcium and prevent osteopenia and osteoporosis.
Vitamin D is also important for several other reasons. Research published in The American journal of the medical sciences has associated D deficiency with an increased risk of cardiovascular disease, including high blood pressure, heart failure, and coronary artery disease. Vitamin D deficiencies have also been linked to diabetes, some cancers, dementia and premature death.
“In addition to immunity-boosting properties, vitamin D is extremely important in metabolic and hormonal optimization because it is involved in insulin sensitivity,” he says Florence Comite, MD, endocrinologist and founder of the Comite Center for Precision Medicine & Health in New York and the Groq Health app. “Indeed, despite its misleading nickname, vitamin D is a hormone.”
How to know if you are low on vitamin D
Your doctor may order a blood test to measure the concentration of 25-hydroxyvitamin D in your body. It’s expensive, and the U.S. Preventive Services Task Force doesn’t support routine screenings. But the only other way to know is by experiencing symptoms such as fatigue, bone pain, hair loss, depression, loss of appetite, or getting sick more easily. But those symptoms could be due to many other causes.
“Widespread deficiency is a vital problem I see in my clinical practice in both men and women, so I prescribe vitamin D for the vast majority of my patients,” says Dr. Comet. “I’ve seen many young women who are low on vitamin D because they don’t eat a lot of dairy products, because they are mistakenly concerned about high fat content in dairy products.”
How to get enough D
Vitamin D₃ (cholecalciferol) can be purchased over the counter. Vitamin D₂ (ergocalciferol), which requires a prescription, is often given to people who have difficulty absorbing D₃.
About 20 percent of the population has a genetic variant that requires prescription vitamin D₂ to metabolize vitamin D in the body, according to Dr. Comet. Additionally, the Institute of Medicine recommends that people ages 70 and younger get 600 international units (IU) of vitamin D daily, and 800 IU if they’re older than 70.
“We typically recommend 2,000 to 5,000 IU per day,” adds Comite.
If you or a close relative has kidney stones, ask your doctor for the correct dose before taking vitamin D supplements. Comite lowers the dose to 2,000 IU if there is a history of stones.
Also, remember that vitamin D is fat soluble, so vitamin D supplements should be taken with a fat source for better absorption. And how about going out in the sun for 60 minutes?
“In my experience, sun exposure doesn’t raise D-levels much,” says Dr. Comet.
Food is another natural source of vitamin D, says Comite. Good sources are vitamin D-fortified milk, yogurt and other dairy products, orange juice and egg yolks, vegetables such as broccoli and mushrooms, and leafy greens such as kale and spinach. Sardines and salmon contain good amounts of vitamin D. A 3.5-ounce can of sardines contains 24% of the Daily Value (DV), while a 4-ounce serving of salmon has 60% of the DV. Here are some great recipes to get a vitamin D boost.
Make sure the D does its job
One challenge is getting enough vitamin D in your body, another is making it useful. In addition to getting vitamin D with fat-containing foods, other nutrients can help you get the most out of vitamin D.
A recent research published in The Journal of American Osteopathic Medicine demonstrated that vitamin D cannot be metabolized effectively if there is not enough magnesium in the body. While magnesium deficiency isn’t a widespread problem, diabetics and people who drink a lot of alcohol tend to lack this important mineral.
Magnesium impacts all the enzymes that activate vitamin D in the liver and kidneys, say the researchers. You can take magnesium supplements. Also, be sure to eat leafy greens, nuts, bananas, yogurt, and fish; all are good sources of magnesium to get the most out of your vitamin D.
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