When you think about vitamin D, you might imagine gulping down a glass of cold milk after performing an afternoon of hard chores. You probably know vitamin D is good for the body. After all, it’s called the “Sunshine Vitamin.” What you may not know is that vitamin D helps your immune system and could help cut down your chance of getting the flu. But are we getting enough of this vitamin? Many people are vitamin D deficient, according to Dr. Steven Joyal, Vice President of Science and Medical Affairs for Life Extension, the largest non-profit organization dedicated to helping people live longer and healthier.

Vitamin D comes from many sources. Joyal, in an interview with Men and Health: It’s a Guy Thing, says it can be found in fatty fish (salmon), mushrooms, fortified dairy products and supplements. Natural sunlight helps the body manufacture this key vitamin. But remember, if you spend time in the sun, take the proper precautions because sun exposure can lead to skin cancer.

While the science is relatively young, Joyal says studies show the health benefits of higher levels of vitamin D. He says a study in the past year indicates that women with high levels of vitamin D, as defined by 25-hydroxy vitamin D status in their blood, had about a 50 percent lower risk of breast cancer. Vitamin D, according to Joyal, not only helps bone and calcium metabolism, but aids in healthy cell growth, division and maturation. “There’s very interesting data out there that really does support the idea that vitamin D not only has a pretty profound effect on our immune system, but also may help in combating the risk of influenza infection,” says Joyal.

How much of this vitamin should we take in a supplement? It depends. Joyal says, “I’m fair-skinned and have blue eyes, so for me, I go out in the sun for 30 minutes at mid-day and easily make 10 thousand international units of vitamin D in my skin.” He says an African-American or Asian person will likely make less in the same period of time. It’s also harder to produce vitamin D from sunlight as we age.

Supplements can help older men and women. Joyal says a study published about a year ago showed that elderly individuals (deficient in vitamin D) who received supplements noticed an improvement in muscle strength, particularly in the lower body. “We know, too, that there are studies showing that vitamin D supplementation seems to decrease the risk of hip fractures.”

When it comes to vitamin D supplements, while Joyal admits there is a difference of opinion, “we believe most people can benefit from at least 2,000 international units a day.” According to Joyal, the best way to discover your vitamin D status is to take the 25-hydroxy vitamin D blood test. “Current research suggests an optimal level of vitamin D is somewhat north of 50 nanograms per milliliter and somewhat south of 80 nanograms per milliliter.”

If you are concerned about the level of vitamin D in your system, Joyal says, “Learn as much as you can, read as much as you can, ask questions of your health care professionals. Doctors tend not to know a heck of a lot about nutrition, quite frankly.” Adds Joyal, you are your most important health advocate.

 Life Extension website: www.lef.org

Information on 25-hydroxy Vitamin D blood testhttp://www.nlm.nih.gov/medlineplus/ency/article/003569.htm