Often nicknamed the “sunshine vitamin,” vitamin D is an important, but frequently misunderstood nutrient. Conflicting news reports and research touting the link between vitamin D and cancer prevention, or debating the pros and cons of vitamin D supplements, have only added to the confusion.
While the jury may still be out on vitamin D’s role in immunity or disease prevention, one thing is clear — our bodies need adequate vitamin D levels for proper health, according to Parthajeet Chowdhuri, MD, an internal medicine physician at Scripps Clinic Rancho Bernardo.
“Vitamin D helps our bodies absorb calcium and maintain normal levels of phosphorus, making our bones strong and helping to prevent rickets in children and osteoporosis in adults,” says Dr. Chowdhuri.
The nickname, the “sunshine vitamin,” originates from the simple fact that our bodies produce vitamin D when exposed to sunshine, specifically the sun’s ultraviolet (UV) rays. While many of us will get all the vitamin D we need from sun exposure, others will need to get vitamin D through other sources as well.
These include people who spend a lot of time indoors, whether it’s due to an office job or because you’re at home for health reasons. Additionally, while sunscreen use is critically important to preventing skin cancer, its continuous use may hamper vitamin D production because sunscreens help block UV rays.
“Of course people need to protect themselves against developing skin cancer. However, there are healthy, moderate levels of unprotected sun exposure that can be helpful in boosting vitamin D. We are not talking about sunbathing at the beach, but a short walk with exposed legs and arms can help.”
Vitamin D is found in some foods including egg yolks, cheese, pork, fortified milk and cereals and fatty fish such as salmon, tuna and mackerel.
“While you can also purchase over-the-counter vitamin D supplements, please talk to your doctor before taking any to determine whether you actually need them and what dose is appropriate,” says Dr. Chowdhuri. “Too much vitamin D can be harmful to your health.”
Certain people are more prone to vitamin D deficiency. In addition to people with limited sun exposure, those who are at higher risk include the elderly, obese or those who have a darker skin complexion. Additionally, certain medical conditions such as celiac disease and Crohn’s disease can cause a deficiency of vitamin D.
Because symptoms of vitamin D deficiency may not be obvious, it’s important not to diagnose yourself. Your primary care doctor can check your vitamin D levels with a simple blood test. The Endocrine Society recommends between 40 and 60 nanograms per milliliter (ng/ml) for adults.
If you are vitamin D deficient, your doctor will work with you on a course of treatment that may include careful sun exposure (to minimize skin damage from UV rays) and the proper use of vitamin D supplements.