Vitamin D Benefits

Getting enough vitamin D protects your health in a variety of ways.

"It's very important to optimize your intake of vitamin D to help support bone health," says Rebecca Drayer, a registered dietitian at Northwestern Memorial Hospital in Chicago. "There's a greater risk of bone fractures if vitamin D levels are low because this may cause less calcium to be stored in the bones."

Vitamin D is also essential for good muscle function, says Sandra Arevalo, a registered dietitian who is the director of community and patient education at Montefiore Nyack Hospital in Nyack, New York.

"It aids in the absorption of calcium and phosphate, which are essential to muscle contractions," Arevalo says.

Benefits of Vitamin D

Here are seven benefits of vitamin D:

1. Improved bone health. Vitamin D increases calcium and phosphorus absorption in the gastrointestinal tract and can help prevent osteoporosis, a disease that causes bones to become weak or brittle, says registered dietitian Sonya Angelone, a San Francisco area-based registered dietitian and spokesperson for the Academy of Nutrition and Dietetics. Vitamin D can increase bone density when supplemented to breast-fed infants.

2. Reduced risk of heart disease, hypertension and all-cause mortality. Research published in Scientific Reports in 2020 suggests that, for people who have vitamin D deficiency, taking supplements of the vitamin "had a favorable effect on diastolic blood pressure levels and parathyroid hormone concentrations" in comparison with people in a control group. "Therefore, vitamin D may be recommended to be used as an adjunct therapy to routine treatment in coronary artery disease patients with vitamin D deficiency."

Previous research suggests that vitamin D can help lower the risk of hypertension and all-cause mortality.

3. Asthma management. Research suggests that vitamin D can be effective as a supplementary therapy for managing asthma, according to a study published in the journal Cureus in 2017.

4. Lower inflammation in people with heart failure. A meta-analysis published in 2018 in the journal Scientific Reports suggests that while vitamin D "may not be effective as a sole treatment to improve inflammation ... it may be beneficial as an adjunct to existing therapies in vitamin D-deficient patients with (heart failure)."

5. Lower risk of several chronic conditions. Vitamin D deficiency is associated with several chronic conditions, including cancer, cardiovascular disease, diabetes and immune system disorders, according to research published in 2017 in the journal Aging and Disease. "Having a healthy vitamin D level may improve blood sugar control for people with or at risk for diabetes," Angelone says.

6. Improved calcium absorption in the small intestine. Having adequate vitamin D levels in the blood boosts the absorption of calcium in the small intestine. "It's important that calcium is absorbed in the small intestine, as then it makes its way into the bloodstream where it can help to build bones and regulate how blood vessels, muscles and nerves function," Drayer says.

7. Improved mood. A small research study found that consuming vitamin D supplements helped improve the depressive symptoms of women with Type 2 diabetes, though there was not a control group against which to compare them. The study was published in 2017 in Hindawi, a commercial publisher of, among other things, peer-reviewed scientific journals. The research, known as the "Sunshine Study," involved 50 women with Type 2 diabetes and significant depression, most of whom were Vitamin D deficient at the start of the study.

Spending time in sunlight is one way of obtaining vitamin D, as the hormone-like vitamin is actually produced in our skin in response to sunlight exposure. "There isn't much sunlight in the winter, (when) many people feel more anxious and depressed, which could partly be a result of low vitamin D," says Maggie Michalczyk, a registered dietitian based in Chicago.

How Much Vitamin D Do You Need?

The recommended dietary allowance for vitamin D for both males and females between the ages of 14 and 70 is 15 micrograms, or 600 international units, according to the National Institutes of Health, Office of Dietary Supplements. Men and women older than 70 should consume 20 micrograms of vitamin D daily, or 800 units.

Older adults are at a higher risk of vitamin D deficiency which is why they need a little bit more. Chances are they are not getting outside for sunlight as much and vitamin D production in the skin becomes less efficient as you age.

Ways to Get Vitamin D

You can get vitamin D from food, sunlight or supplements, Michalczyk says. Ask a registered dietitian or your health care provider whether supplements are right for you.

These foods are good sources of vitamin D: