There’s been a flurry of recent media attention touting vitamin D as a sort of super-nutrient. So what’s the deal: Is it just media hype du jour, or should you worry about your daily intake of the sunshine vitamin?
Irina Haller, M.D., thinks you ought to be concerned. “Vitamin D deficiency is linked with the development of osteoporosis and osteomalacia [softening of bones], and more recently with the increased risk of falls,” said Haller, a senior research scientist at the Division of Education and Research at the Duluth Clinic and assistant professor at the University of Minnesota-Duluth medical school. “Low vitamin D status has [also] been associated with infection and immune dysfunction …[and] recent epidemiological studies linked vitamin D deficiency with the increased risk of multiple sclerosis, hypertension, diabetes mellitus and cancer.”
Minnesota women at risk
Minnesotans in particular should be careful of their vitamin D levels, Haller said. “People in cooler climates … are more likely to be vitamin D deficient, since vitamin D production in the skin is reduced or does not occur due to the low angle of sun rays,” she said.
According to Patricia Walker, M.D., medical director at Health Partners Center for International Health and Travel Medical Clinic and staff physician at Health Partners Center for Women, osteoporosis is the most significant of these risks. As women age, the risk of osteoporosis increases substantially, with women 65 and older at highest risk. “Women are … at higher risk of osteoporosis than men, and vitamin D is important in calcium metabolism and bone strength,” Walker pointed out.
Vitamin D deficiency has once again reached epidemic proportions in the U.S., especially for women, according to the American Society for Nutrition.
An important study recently showed that vitamin D deficiency was a significant factor in the progression and survival rate of breast cancer. Women with insufficient levels of the vitamin may also be at higher risk of developing preeclampsia during pregnancy. Still other studies point to potential side effects of vitamin D deficiency that include muscle pain, fractures, low energy, depression, sleep irregularities, weight regulation, seasonal affective disorder, birth defects and even PMS.
While she says it’s difficult to pinpoint exactly how many women in Minnesota are deficient, Haller pointed to studies that report anywhere from 42 to 90 percent of women whose levels of vitamin D were not considered sufficient. “If I would have to guess based on the limited information that is available, at least half of the adult population in the state may be vitamin D insufficient,” she said.
Because a deficiency is often difficult to detect until problems develop, most of the half of us who are deficient aren’t even aware that we have an issue that could potentially pose a serious threat to our health.
National Institutes of Health www.nih.gov
Vitamin D Council www.vitamindcouncil.org
National Osteoporosis Foundation www.nof.org
The ABC’s of vitamin D
Vitamin D is a fat-soluble vitamin that naturally occurs in some foods, including cod liver oil, mackerel, salmon and tuna. It is added to others-such as milk, some soy milk, breakfast cereals, and some brands of orange juice-and can also be taken as a dietary supplement. Our bodies can produce vitamin D endogenously if we get sufficient exposure to the sun, which is a lot more challenging than you may think.
Smog, cloud cover, and window glass all prevent the synthesis of vitamin D through the skin. People aged 50 and over are at risk because the skin’s ability to produce vitamin D diminishes with age, and women who wear a head covering and long robes can’t get enough exposure to produce sufficient amounts. Darker skin doesn’t produce vitamin D easily, because greater amounts of melanin reduce the skin’s ability to produce it. And sunscreen? Forget it when it comes to trying to soak up the vitamin D rays, say the experts.
Of course balancing the need for vitamin D with skin cancer protection is important, Walker said. She recommends that Caucasian women “expose from your elbows down and your knees down to the sun for 15 minutes a day.That is adequate for vitamin D synthesis during the summer months. … You obviously want to balance not being out in the sun for hours to get your vitamin D, but just a small amount of exposure every day is enough.” Walker added, “If you are African-American, it may take as long as 60 minutes per day to obtain adequate vitamin D from the sun.”
Are you getting enough?
“In Minnesota from November through March, the sun is so far south on the horizon that you cannot synthesize enough vitamin D in your skin even if you go outside in February with exposed arms and legs, which people are much less likely to do,” Walker said.
Even those of us who spend much more time out in the sun than we know we should could be at risk, according to Walker. We may not be able to store up enough vitamin D over the summer to get us through the Minnesota winter. “It depends on what your baseline vitamin D stores are. … If you go into summer very vitamin D deficient from the previous winter, you may not be able to store up enough over the summer to last you through the next winter, so the best thing to do is just make sure you’re getting enough vitamin D year ’round,” she said.
And, to make matters worse, Haller added, “Since only very few foods contain vitamin D naturally or [are] fortified with vitamin D, it is almost impossible to achieve sufficient levels of vitamin D through diet.”
Most experts agree that the best way to guarantee sufficient levels of vitamin D is to take a supplement, especially during the winter months in northern climates. “General recommendations are 800-1000 International Units (IU) per day,” Walker said. She recommends checking any supplements, including calcium with vitamin D added, that you may already be taking before adding additional amounts. Dr. Walker stressed that it is critical for women of all ages to get enough of the nutrient. “Vitamin D should be a part of one’s diet lifelong,” she said.
How can you find out if your levels of vitamin D are too low? “In northern environments, more physicians are checking as part of a routine preventive exam,” said Walker, who tests all of her patients, regardless of their age, “and women can certainly request it.”
Walker recommends that all women get tested at least once yearly, “Ideally in the fall just before the sun is starting to head southward, or in the springtime after the winter to see if you’re vitamin D deficient,” she said.
What it means for you
Ask your physician to test your level of vitamin D and ask for recommendations to help you either increase or maintain your level of the nutrient based on your particular needs.
Consider your risk factors and educate yourself by looking for books and articles on vitamin D, be mindful of how much time you are exposed to unfiltered sunlight, read labels to check the levels of vitamin D in your food, and consider taking a supplement, especially during the winter months.
“Our grandmothers and our great-grandmothers used to recommend cod liver oil, at least in the winter, because they knew that, living in northern environments, we would be more likely to be deficient,” Walker said.
Turns out grandma knew best.