You want to stay lean and keep your arteries clog-free, so you’re a strict vegan. In trying to prevent skin cancer – not to mention unsightly wrinkles – you stay out of the sun, and when you do venture outside, you slather on the SPF 50 sunscreen.
Your efforts to stay healthy, however, could be setting you up for a myriad of health issues related to vitamin D deficiency.
Vitamin D is an essential fat-soluble vitamin necessary for the absorption of calcium so important to develop and maintain strong bones. A vitamin D deficiency can lead to soft, thin, and brittle bones, a condition known as rickets in children and osteomalacia in adults. Vitamin D is also thought to play a role in preventing osteoporosis, high blood pressure, some types of cancer, and several autoimmune diseases, including multiple sclerosis.
A lack of vitamin D may also increase the chance of muscle injuries in athletes, specifically NFL football players, according to a study released earlier this month. "Eighty percent of the football team we studied had vitamin D insufficiency. African American players and players who suffered muscle injuries had significantly lower levels," lead researcher Michael Shindle, M.D., said in a news release about the study.
Few natural foods contain vitamin D, according to the National Institutes of Health. Fish liver oils — old-fashioned cod liver oil — and fatty fish such as salmon and tuna are good sources. Beef liver, cheese, and egg yolks also contain small amounts of vitamin D. Fortified milk, bread and breakfast cereals are the primary source of vitamin D in the diets of most people.
Many people meet at least some of their vitamin D needs through exposure to sunlight. There is no need to bake in the sun to prevent a vitamin D deficiency. Just 10 to 15 minutes of sunshine a day is more than enough to produce the body's requirement of vitamin D.
People at risk for a vitamin D deficiency include:
those who are lactose intolerant and avoid dairy products;
those who are strict vegetarians and don’t include fish, eggs and milk in their diet;
those with dark skin because their skin has less ability to produce vitamin D from the sun;
older adults because their skin doesn't produce vitamin D when exposed to sunlight as efficiently and their kidneys are less able to convert vitamin D to its active form;
those with disorders such as Crohn's disease or celiac disease who don't handle fat properly, because vitamin D needs fat to be absorbed;
those who are obese because fat cells prevent vitamin D getting into the blood;
those who have limited exposure to sunlight.
The recommended dietary allowance (RDA) of vitamin D is 600 international units for anyone under 70 and 800 IU for those over 70. Many multi-vitamin tablets will provide an adequate daily amount of vitamin D.