Are you one of 1 billion?

Believe it or not, 1 billion people worldwide are deficient in vitamin D. Vitamin D is known as the "sunshine vitamin," because it can be synthesized in our skin while we're out in the sun. We've known for years that inadequate vitamin D can affect your mood (heard of the winter blues??), but we continue to learn that it can affect much more.

Researchers have found that there are vitamin D receptors on the pancreas, the prostate, breast tissue, the colon, macrophages (which protect your immune system), the kidneys (regulate blood pressure) and the parathyroid gland. Woah! How many common health problems could be related to insufficient levels of vitamin D?

Although this subject has been getting tons of attention lately, I'm bringing it up now because I attended a great seminar last week on vitamin D. So good in fact, that I even found myself wondering if I could possibly have insufficient levels of vitamin D. Dietitians aren't perfect after all (however hard we may try)! But it makes sense--there aren't that many food sources that contain vitamin D, they're easily eliminated from people's diets and most of us don't go out in the sun that much any more. If you don't eat fish, don't consume several servings of dairy a day and/or aren't in the sun (with most of your body exposed) for at least 15 minutes per week, you could be one of the 1 billion with a low vitamin D level.

The good news is that this problem is easily remedied. The Institute of Medicine now recommends that people ages 1 to 70 consume 600 IU vitamin D daily. If you are overweight or obese, you might require 2 to 3 times more vitamin D! The best food sources of vitamin D are fortified dairy products and fatty fish like salmon, tuna, mackerel and sardines (double bang for your buck here--you also get a good helping of healthy omega-3s).

You can get all the vitamin D you need "naturally" by consuming three servings of fortified dairy products daily, fatty fish at least twice per week and basking in the sunlight without sunscreen (or yes...getting UVBs from the tanning bed) once a week. Give it your best shot because getting our nutrients from food is best, if possible. However, most of us would probably benefit from a low-dose supplement just in case we're lacking for the day. But this should be just insurance! A plain-old multivitamin typically contains 400 IU vitamin D and is a good back-up plan. But if you're already deficient in vitamin D, this won't be enough to increase your levels back to normal range. And of course, there are many causes of vitamin D deficiency, not just inadequate diet. If you feel symptoms of low vitamin D (muscle pain, fatigue, decreased immunity) or think you may be at risk, discuss vitamin D testing and supplementation with your doctor.

Although evidence-based and as accurate as possible, advice given in this column should not be used as a substitute for personal medical attention from your physician. Always check with your physician before making any changes to your medications, over the counter or prescription.