What are health benefits of vitamin D?

Dariush Mozaffarian, MD
Internal Medicine
The following are health benefits of vitamin D (calciferol):
  • Helps maintain normal blood levels of calcium and phosphorus, which strengthen bones
  • Helps form teeth and bones
  • Supplements can reduce the number of nonvertebral fractures
Vitamin D, also called the "sunshine vitamin," has many health benefits, a number of which have been discovered only recently.

Vitamin D helps your body absorb calcium, so it's essential for bone health. Getting enough vitamin D helps keep bones strong and may help prevent osteoporosis.

Emerging research shows that vitamin D may help prevent cancer, though experts say more study is needed. Other studies have pointed to the possibility that vitamin D may help prevent and treat type 1 and type 2 diabetes and high blood pressure. And low levels of vitamin D have been linked to a worsening of multiple sclerosis symptoms.
A number of studies have found that higher vitamin D, which the body makes using sunlight, protects against some cancers and illnesses, such as rickets, bone-thinning osteoporosis, and diabetes. It also helps the body’s immune system work properly. Certain foods and vitamin supplements contain vitamin D, but the main source for the body is the sun. It only takes ten to twenty minutes of sunlight a few times a week to make plenty of vitamin D. Still, if you spend most of your time indoors and/or live in the northern half of the country, producing enough D can be problematic, especially in winter.
Joseph M. Mercola, DO
Family Medicine

Family Physician and Integrative Health Specialist Dr. Joe Mercola discusses the health benefits of vitamin D. Watch Dr. Mercola's video for tips on overall health and wellness.

Ms. Ashley Koff, RD
Nutrition & Dietetics
Vitamin D has gained a lot of attention in recent years due to an enormous body of research confirming its role in human health and the fact that we don't get enough of it. It's not just a result of us working indoors all day and protecting ourselves from the sun's damaging rays, but it's also a consequence of geography. The vast majority of people who live in North America can't get the same amount of sunlight as those closer to the equator. It's easy for the body to manufacture plenty of vitamin D from brief exposure to UVB radiation a few times a week, but it's very hard to get that same amount of vitamin D from diet alone.

Why is this vitamin so important? It's actually a hormone critical to survival because it has a role in numerous communications. A number of studies have found that higher vitamin D, which the body makes when sunlight hits the skin, protects against some cancers and illnesses such as rickets, bone-thinning osteoporosis, and diabetes. It also helps the body's immune system work properly, reduces inflammation, and plays a role in muscle, cardiac, immune, and neurological functions. If you're not casually exposed to sunlight or brief periods a few days a week ("brief" meaning ten to fifteen minutes and long before you'd begin to burn), consider adding a vitamin D supplement that has at least 1,000 IU to your daily regimen.

Mom Energy: A Simple Plan to Live Fully Charged
Dr. Rovenia Brock, PhD
Nutrition & Dietetics
Vitamin D has emerged as a "star supplement" because of its many nutritional benefits for men, women and children. Vitamin D plays a key role in the proper absorption of calcium for strong bones and teeth and has been shown to support colon, breast, prostate, ovarian, heart and colorectal health. This important vitamin also supports a healthy immune system in adults. Unfortunately, too many Americans have suboptimal levels of vitamin D. The typical symptoms of vitamin D deficiency are achy bones and muscle discomfort.
Dr. Michael Roizen, MD
Internal Medicine
Vitamin D is essential for proper absorption of calcium. Vitamin D helps strengthen bones and prevents the joint deterioration that accompanies arthritis. Vitamin D and its metabolites also appear beneficial in reducing certain kinds of breast, colon, prostate, and lung cancers.
Dr. David L. Katz, MD, MPH
Preventive Medicine
Watch as preventive medicine specialist Dr. David Katz explains the health benefits of vitamin D.
Vitamin D is considered a hormone as well as a vitamin for its role in body processes. It works together with calcium and phosphorus to strengthen bones and teeth, and aids in assimilation of vitamin A. Vitamin D may also help eye problems such as conjunctivitis, myopia, and cataracts.
Dr. Mehmet Oz, MD
Cardiology (Cardiovascular Disease)
Vitamin D plays a number of roles in our bodies, including:
  • Promoting absorption of calcium and bone health
  • Boosting immune function
  • Reducing inflammation
  • Healthy neuro-muscular function
  • Protecting against some forms of cancer
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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.