You probably know that vitamin D is important for strong bones, but new research shows it has many extra health benefits as well. Our bodies make vitamin D when we are exposed to sunlight; that’s why it’s sometimes called the “sunshine vitamin.” Yet, it is difficult to get all our vitamin D needs from the sun. Nowadays, many people have limited exposure to the sun. More than one billion people worldwide suffer from a deficiency (1).

These are the basic facts about Vitamin D and some easy ways to ensure you’re getting enough.

Basic Facts About Vitamin D

  1. Vitamin D strengthens your bones. Vitamin D is a hormone. It controls calcium absorption and builds strong bones and teeth. This can help reduce your risk of osteoporosis.
  2. Vitamin D protects your physical health. Vitamin D is effective for certain thyroid disorders, psoriasis, and skeletal problems associated with chronic kidney disease (2). Optimal vitamin D levels over a long period of time are also associated with decreasing the likelihood and severity of type 1 and type 2 diabetes, heart disease, rheumatoid arthritis, and certain cancers (3).
  3. Vitamin D protects your immune system. Vitamin D plays an important role in having a healthy immune system. Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, explains that, “Vitamin D does have an impact on your susceptibility to infection.” (4) However, scientists are still studying the link between vitamin D and COVID-19 infections. There is conflicting evidence related to vitamin D levels and protection against COVID-19 infection or disease severity. At this time, there is no evidence that one should supplement with vitamin D beyond the levels recommended for general health.
  4. Vitamin D may have mental health benefits. Vitamin D may help you to think and feel better. In older adults, it’s been found effective in improving cognitive functions and alleviating depression (3).
  5. There are risk factors for vitamin D deficiency. As we age, our kidneys must work harder to convert vitamin D into its active form, so we may need supplements. The same is often true for mothers breastfeeding infants, people with darker skin, and those with conditions like Chrohn’s disease or milk allergies (5,6).
  6. Vitamin D levels vary by age and stage of life. The Recommended Dietary Allowances (RDAs) for vitamin D are listed here. The RDA amounts vary by age and range from 10mg (400IU) for infants up to 12 months of age, to 20mcg (800IU), for adults older than 70 years old. However, it is important to keep in mind that the RDAs are for maintaining bone health and calcium metabolism. Depending on a person’s age and medical condition, some individuals may need 50mcg (2,000 IUs) to 100mcg (4,000 IUs), which is still regarded as safe. Consult with your health-care professional to determine your optimal level of vitamin D.
  7. A blood test can tell you what your vitamin D level is. While bone pain and muscle weakness are possible, the symptoms of vitamin D deficiency are often very subtle. Your doctor can give you a simple blood test to be sure. It is called a 25 hydroxyvitamin D test, and blood levels greater than 20 ng/ml are considered adequate for bone and overall health (7).
  8. Talk with your doctor or pharmacist about drug interactions. Some drugs like steroids, can lower vitamin D levels while others, like statins can raise them. Your doctor can help you find a safe level for you (7).


Easy Ways to Get Enough Vitamin D

  1. Be smart about sun exposure. Keep using your sunscreen to prevent skin cancer and premature aging. Even though sunscreen with an SPF of 8 or more blocks vitamin D producing UV rays, most people do not cover all exposed skin or use enough sunscreen to block all vitamin D synthesis.
  2. Drink your milk. Only a few foods contain vitamin D naturally, but many are fortified with it. Almost all milk in the United States supplies at least 400 IU per quart, which is the main reason why the bone disease rickets has virtually disappeared.
  3. Eat more fatty fish. Fish and fish oil are among the most potent sources of vitamin D. Three ounces of salmon covers 71% of your recommended Daily Value (DV). Three ounces of light canned tuna provide 5% of your recommended DV.
  4. Add vitamin D-fortified foods to your diet. Good choices include yogurt, breakfast cereals and orange juice. Check the labels to be sure of what you are getting.
  5. Eat a variety of foods. White mushrooms provide 46% of the recommended DV. Eggs and cheddar cheese also contribute small amounts of vitamin D.
  6. Consider supplements. Supplements come in two forms. Both D2 and D3 versions are good for you, but D3 is the better choice. It is closer to the natural vitamin D your body produces, so the effects last longer (7).


Vitamin D is important for your bones and overall health. Meet your requirements through sensible sun exposure and a healthy diet, or talk with your doctor if you think you need supplements.



  1. Sahota, O. (2014, September). Understanding vitamin D deficiency. Retrieved January 25, 2021, from
  2.  Morrow, K. (2016). Chapter 12 Food and Nutrient Delivery. In 1164630344 874042679 L. K. Mahan & 1164630345 874042679 J. L. Raymond (Authors), Krause’s food & the nutrition care process (p. 201). St. Louis (Mo.): Elsevier.
  3.  Wimalawansa, S. (2016, September 20). Non-musculoskeletal benefits of vitamin D. Retrieved January 25, 2021, from
  4. Rubin, R. (2021, January 06). Does Vitamin D Deficiency Raise COVID-19 Risk? Retrieved January 25, 2021, from
  5.  La Leche League International. (2020, August 06). Vitamin D, Your Baby, and You. Retrieved January 25, 2021, from
  6.  Ham, M., Longhi, M., Lahiff, C., Cheifetz, A., Robson, S., & Moss, A. (2014, May). Vitamin D levels in adults with Crohn’s disease are responsive to disease activity and treatment. Retrieved January 25, 2021, from
  7.  National Institute of Health Office of Dietary Supplements. (n.d.). Office of Dietary Supplements – Vitamin D. Retrieved January 25, 2021, from