Many people take a multivitamin supplement each day—it makes you feel like you are filling in the gaps where your diet might be lacking. But, did you know your multivitamin may not be giving you one very important vitamin, vitamin D?
How does it work? Vitamin D plays several key roles in your body. Most importantly, it helps your body absorb the minerals calcium and phosphorus. These minerals are essential for strong, healthy bones; not absorbing enough can lead to weak bones and bone pain.
Most vitamin D you intake—80% to 90% of what your body gets—is through exposure to sunlight, giving it the nickname the sunshine vitamin. Sun exposure is an easy, reliable way for most people to get vitamin D. How much does it take? Sun exposure two to three times a week, for about one-fourth of the time it takes to get sunburned, is enough. Just six days of casual sunlight exposure without sunscreen can make up for 49 days of no sunlight! Body fat acts like a storage battery for vitamin D—during periods without sunlight, vitamin D is released through the bloodstream. That is important to know as we enter the colder months where sunlight and outdoor activity lessens.
Who might need a vitamin D supplement? People who have low levels of vitamin D may need supplements. Vitamin D deficiencies are more common in people who have:
- Little exposure to sunlight. If you are homebound (most often the elderly), live in northern parts of the U.S., or have an occupation that prevents sun exposure your body might be at risk.
- Dark skin. The pigment melanin reduces the skin’s ability to make vitamin D in response to sunlight exposure. Some studies show that older adults with darker skin are at the highest risk of vitamin D deficiency.
- Kidneys that cannot convert vitamin D to an active form (common as people age).
- Digestive tracts that cannot adequately absorb vitamin D (people who suffer from Crohn’s disease, cystic fibrosis, and celiac disease).
Treatment for D deficiency: If you think you may have a vitamin D deficiency, talk with your doctor who can do a quick blood test to determine your needs. Although there is no consensus on optimal vitamin D levels, most doctors agree a blood test resulting in a level of less than 20 nanograms per milliliter could mean you are deficient.
Did you know? Research suggests that vitamin D could play a role in the prevention and treatment of a number of different conditions, including type 1 and type 2 diabetes, hypertension, glucose intolerance, and multiple sclerosis.