Believe it or not, winter is approaching.
The days are getting perceptibly shorter every week. With the diminishing sunlight, your skin is losing the solar power it uses to make vitamin D. The skin can make about 1,000 IU vitamin D from 30 minutes of direct exposure to summer sun without sunscreen. That’s also enough to give you a substantial sunburn, especially here in the southwest, so I don’t recommend it.
Vitamin D is best known by the company it keeps: calcium. Vitamin D helps our bodies absorb calcium from the intestine. Calcium is a building block for teeth, bones and nails. It is also vital for muscle contractions and blood vessels, function of nerves and hormones and enzymes secretions. We have more calcium in our bodies than any other mineral. The classic condition of low calcium is osteoporosis, or thin bones.
But more than just a sidekick for calcium, vitamin D has been in the spotlight recently because new studies suggest that it is good for many body functions. Research has implicated vitamin D deficiency as a major factor in at least 17 varieties of cancer as well as heart disease, stroke, hypertension, autoimmune diseases, diabetes, depression, chronic pain, osteoarthritis, osteoporosis, muscle weakness, muscle wasting, birth defects, periodontal disease and more. Indeed, it is looking like this little molecule packs a big punch all on its own.
You don’t have to make vitamin D in your skin. You can get it in your diet, or in a supplement.
For adults, the recommended intake is currently only 200-400 IU a day, available in 2-4 cups of fortified milk, but that is likely to go up as the research expands. Some experts suggest daily intake in the 1,000-2,000 IU range. Most of us probably don’t get or make enough of this vitamin for maximum health.
Many of us have vitamin D insufficiency, which means a level too low for good health, but not low enough to cause symptoms. You might need a supplement. You can ask your doctor for a blood test to find out. For more information, go to MayoClinic.org or VitaminDCouncil.org.
Dr. Margaret Spencer, MD is a board-certified family physician. She has been a UNM student health physician for 17 years. Drop your questions in her box in the lobby of Student Health and Counseling, or e-mail her directly at pspencer@unm.edu. All questions will be considered, and all questioners will remain anonymous. This column has general health information only and cannot replace a visit to a health care provider.
