Vitamin D, also known as cholecalciferol or vitamin D3, has taken center stage in the news recently as concerns are being raised that many Americans are not getting enough. Vitamin D is best known for its role in bone health, but is involved in other regulatory functions in the body as well.

The American Academy of Pediatrics recently announced a recommendation to increase intakes of vitamin D for children and teenagers from 200 IU to 400 IU daily. The recommended level is already 400 IU for ages 51-70 and 600 IU for those over 70. Children who do not get enough of vitamin D can develop a bone deformity known as rickets, which results in a bow-legged appearance. Likewise, adults with low vitamin D levels are at risk for developing the osteoporosis. Milk consumption, which is a significant source of calcium and vitamin D, often decreases as children enter the teenage years and milk is often replaced with soft drinks and other sugary beverages. Many adults also avoid milk products because of intolerances or other dietary restrictions.

Numerous foods are fortified with vitamin D, which means vitamin D was not present in the product originally, but was added during the manufacturing process. Milk, margarines, cereals, and yogurt are only a few. Foods like cod liver oil, herring, mackerel, sardines, and salmon are also good food sources of vitamin D.

It is important to consider that some medications, such as Prednisone, can interfere with vitamin D metabolism. Cholestyramine (Questran), for instance, may interfere with absorption. Check with your physician or pharmacist about drug-nutrient interactions relating to your specific prescriptions.

More isn't always better. One cup of 2% milk contains about 100 IU, but some supplements contain much more. Too much vitamin D (levels above 2,000 IU daily) can cause calcium deposits in bones and organs so it's important to always read supplement labels closely and consult with your physician if you have specific questions about dosages. Remember that supplements are NOT regulated by the FDA nor are they held to the same standards.

Another way to increase vitamin D levels without supplementation is exposure to sunlight. Sunlight triggers a chemical reaction within the skin, which results in the manufacture of vitamin D. For most people, 20 minutes of sun exposure is sufficient. Although the use of sunscreen is often recommended to reduce risks of skin cancer, these products interfere with vitamin D conversion. A #8 sunscreen can reduce vitamin D production by about 95%. Still, using sunscreen is highly recommended if you are planning to be in the sun for extended periods of time.

Many physicians are now testing the serum 25(OH)D levels of patients. Levels below 20 nanograms per milliliter are generally considered low, and levels great than 30 are desired. If you are concerned about your vitamin D level, there are several things you can do. First, consult with your physician and request that your level be tested. If you discover that your level is low, consider making adjustments in your diet to maximize vitamin D intake.