For years, calcium has been considered the gold-medal winner when it comes to optimal bone health. But recently a new champion has been unveiled: vitamin D. And experts are convinced that Americans are coming up considerably short in their consumption of it—especially young ones.
A study reported in the March issue of Medical News Today confirmed that one in seven teenagers in the United States is vitamin D deficient. It also found that more than half of African American teens are vitamin D deficient, and that females are at more than twice the risk of deficiency than males. Overweight teens had nearly double the risk when compared to those of normal weight.
So dance teachers take note and advise your students wisely—vitamin D–deficient diets can lead to stress fractures, scoliosis and osteoporosis, leaving dancers sidelined for weeks or even months, or with permanent damage. Poor nutrition, disordered eating and excessive training can also contribute to suboptimal vitamin D intake. Keep reading to discover how getting the recommended amount of this multitasking vitamin can lead to a long and healthy dance career.
Calcium and vitamin D are key partners in the well-choreographed bone and tooth dance; without them, bones wouldn’t grow stronger. After vitamin D facilitates the absorption of calcium in your stomach, it continues to help the body maintain the correct amount of calcium and phosphorus in the blood. These minerals are essential for normal bone mineralization, growth and remodeling. For a dancer, this means avoidance of thin, brittle or misshapen bones.
Researchers have also found that adequate vitamin D can boost the immune system to help you dodge colds, flu and other nagging illnesses that could keep you out of class and performances. This is in addition to its ability to curb inflammation caused by tough training sessions, performances and competitions, and its positive impact on normal muscle function. Vitamin D is even believed to have a significant protective effect against the development of diabetes and heart disease, along with breast, prostate and colon cancers.
In 2008, the American Academy of Pediatrics (AAP) issued recommendations for the pediatric and adolescent population that exceed those established by the Food and Nutrition Board in 1997. Currently, the AAP recommends that children and adolescents aim for 400 International Units (IU) of vitamin D every day—200 IU more than the previous study. For those who do not obtain 400 IU a day through vitamin D–fortified foods, the AAP recommends a daily 400 IU vitamin D supplement.
However, vitamin D experts believe there is now more than enough evidence to support increasing the recommended vitamin D dosage for all Americans to 1,000 IU, especially during the winter months for some parts of the country. But stay tuned for the final verdict: The Institute of Medicine is revisiting vitamin D and calcium recommendations with a new report expected in the spring of 2010.
If you’re concerned about the possibility of overconsuming vitamin D, don’t fret. The maximum recommended intake since 1997 has been 2,000 IU, but a 2007 risk assessment suggested that healthy adults can easily tolerate as much as 10,000 IU.
Vitamin D–Enriched Diet
There are only a few natural food sources of vitamin D, including fatty fish and fish oils. (Three and a half ounces of cooked mackerel, salmon, halibut and sardines contain 270 to 360 IU of vitamin D.) Consuming fatty fish at least two times a week will not only boost your vitamin D level, it will also provide your body with heart-healthy, inflammation-preventing omega-3 fats.
Most other foods high in vitamin D have been fortified, such as milk and yogurt (100 IU and 80 IU per eight ounces, respectively), margarine (60 IU per tablespoon), some cereals (40 to 50 IU per 3/4 cup) and orange juice (100 IU per eight ounces). Aim for two to three servings of low-fat, vitamin D–fortified milk or yogurt each day, in addition to a variety of vitamin D–fortified foods.
Vegetarians who avoid dairy should take a daily multivitamin-mineral supplement with meals that contains at least 400 IU of the more absorbable vitamin D3, also known as cholecalciferol, versus vitamin D2. And when checking food labels, be aware that the Daily Value (DV) is understood as 400 IU, so aim for 100 percent of the DV and don’t be shy to consume 200 percent of the DV (800 IU). (See page 100 for an ideal meal plan.)
Unlike any other nutrient, vitamin D can be produced in the skin when it’s exposed to natural sunlight. Fair-skinned individuals should aim for 10 to 15 minutes of unprotected sun exposure to the face, arms and hands two to three times a week, and those with dark skin can get 30 minutes. (Best time is between 10 am and 3 pm.) But don’t worry. Excessive exposure to the sun cannot result in vitamin D toxicity, since constant heat on the skin causes this vitamin to degrade, and the older you are, the less efficient your skin is at making vitamin D from the sun.
There are a few catches, however, when it comes to relying solely on the sun to meet your vitamin D requirements. If you use sunscreen with an SPF of eight or greater, your body’s ability to synthesize vitamin D is drastically reduced. Put sunscreen on right before heading outside, since it takes at least 20 minutes for this product to become fully effective. And for those living north of an imaginary line between Los Angeles and Atlanta, Georgia, your skin is unable to synthesize any vitamin D between the months of November and February, due to less sunlight.
And what about using alternative sunning methods, like tanning beds, if you’re strapped for time? The ultraviolet rays in tanning beds can produce vitamin D in your skin, but don’t be fooled—they can cause deadly skin cancer. Instead, implementing a balanced combination of foods, supplements and natural sunlight is a much safer bet to ensure you get your necessary Ds. DT
Karlyn Grimes is a registered dietitian and a nutrition and biology faculty member at Simmons College in Boston.
Put More D in Your Diet
Not sure if you’re getting enough vitamin D? Take note of the following sample menu for a diet that will provide more than 850 International Units of vitamin D. Add a daily multivitamin, and you will easily meet the current vitamin D recommendation of 1,000 IU. Enjoy!
3/4 cup whole grain, vitamin D–fortified cereal (50 IU)
1 cup low-fat milk (100 IU)
1 cup vitamin D–fortified juice (100 IU)
Turkey sandwich on two slices of vitamin D–fortified whole-grain bread (40 IU)
Low-fat yogurt sprinkled with vitamin D–fortified, whole-grain cereal (125 IU)
3 1/2 ounces salmon (360 IU)
Large colorful salad
1 cup low-fat milk (100 IU)
Photo copyright iStockphoto.com/James Brey