By Suzanne Martin, PT, DPT
Got sunlight? Of course. Well, maybe—depending upon the season, how far you are from the equator, and how much sunblock is in your moisturizer. We all know that a little sunlight can make us feel better, and most of us know that it’s a source of Vitamin D. Yet how many dancers do you see with a George Hamilton tan that’s not painted on? In my studio experience I’ve seen many a pasty face; even in Miami Beach, Phoenix, or San Diego, beaucoups hours of teaching, rehearsing and performing can keep even the most devoted sun-child indoors. And what about the ozone-layer scare? Most dancers with experience (read: age) tend to wear sunscreen not just for melanoma prevention but also out of vanity. We all want to stay wrinkle free as long as possible.
Why does Vitamin D matter? For starters, it plays an important role in bone density, especially in women. The American College of Sports Medicine and the International Association for Dance Medicine and Science have made groundbreaking statements about the incidence of amenorrhea, osteoporosis, and stress fractures in female athletes and dancers. It is now well known that dancers, especially the young, need to eat enough calories to sustain the energy level necessary to excel in dance and avoid the risk of imminent stress fractures and down-the-line osteoporosis that often accompanies low blood levels of estrogen. Now we have one more important piece in the well-dancer/strong-bone puzzle—Vitamin D—thanks to recent research spearheaded by Dr. Michael Holick and others at Boston University School of Medicine.
What is a vitamin, anyway?
Technically, a vitamin is a catalyst for necessary chemical reactions that make our cells and tissues function well. “Vitamin D” is a nickname because now we know that it is actually a full-blown hormone, a chemical messenger with functions that go beyond the all-important role of bone manufacture.
Sources of Vitamin D
Most people now know something about the so-called “sunshine vitamin.” The traditional belief was that we get enough Vitamin D from sunlight. But after health officials discovered Vitamin D deficiency’s link to bone problems in sun-deprived slum dwellers in Warsaw and London in the late 1800s and early 1900s, D began its roughly 100-year history as a food additive into such products as milk and juice. Severe deficiency creates undeveloped bones in children (rickets) and fractures in adults (osteomalacia).
According to Holick, in about 1930 U.S. government regulations slackened the requirements regarding Vitamin D as an additive; the problem was solved. But was it? Frightening research from Dr. Holick tells us it likely is not. His recent studies on human blood levels at various latitudes, the true amount available in milk and juices, blood-level findings across skin color, and the amount of sunshine that actually passes through glass are reason enough to pay attention.
Holick’s argument for Vitamin D supplementation to avoid deficiency is profound. The farther you are from the equator, the less D you absorb. Plus, you need a large amount of leg, arm, and facial skin exposure, for about 15 minutes 4 times a week, to get the minimum. The amount found in juices and milk often varies from the stated packaging. Dark skin colors and the filtration effect of glass block the beta ray exposure necessary for Vitamin D production.
Dancers at risk
Both baby ballerinas and seasoned masters appear to be at risk for a double whammy of shaky bone health. Young dancers run the risk of low estrogen levels and body weight having a negative impact on bone production and density; add the factors of geographic location, skin color, and limited exposure to the outdoors to create a tricky skeletal situation. Older dancers share those geographic, skin, and cultural issues, and those who are post-menopausal have a recipe for fracture if they don’t take preventative measures. In younger dancers, think stress fractures; in older dancers, think hip replacement. Add the fortunately going-out-of-style cultural behavior of smoking and/or consuming sodas to either demographic, and you’ve got a surefire recipe for disaster.
What if you don’t care about bone health? Isn’t that an abstract idea? Don’t those problems happen to other people? Not really. All dancers can relate to muscles. Muscles equal technique; muscles dictate control. Muscles determine how you look onstage and whether you have the strength to execute an entire variation. Yet the real zinger is that muscles can only be as strong as the bones they pull on. Soft, hollow bones mean little muscle strength. In the flexible body type of the typical dancer (called hypermobility), muscle strength translates into less joint pain, fewer sprains, and generally less body pain. And to have strong muscles you need strong bones.
How much is enough?
Are all dancers doomed? The good news is that Holick’s research caused other researchers to jump on the Vitamin D bandwagon, and they have some concrete recommendations. The recommended daily allowance has been bumped up to 1,000IU from its previous levels of 400IU for children over age 4 and 600IU for postmenopausal women. Another recommendation is to have your blood level of D2-OH measured; a minimum value of 40 ensures the bone strength necessary for good muscle tone.
An adequate amount of Vitamin D, along with the recommended daily allowance of 1,200 to 1,500 milligrams of calcium for adolescent dancers and post-menopausal dancers, respectively, is crucial to bone deposition. There is now evidence of Vitamin D’s influence on other important physiological functions that have an impact on cancer risk and immune disorders. That means that everyone, especially those watching their caloric intake, needs a multivitamin supplement for basic nutrition.
An often-asked question is how to get it naturally in food sources. The obvious ones are D-fortified milk and juices. Unfortunately Vitamin D occurs best in cod liver oil, not a favorite food for most of us. That’s why supplementation makes sense. Look for the D3 form in supplements and heed the 1,000IU level for a daily dose.
The farther you are from the equator, the less Vitamin D you absorb. Plus, you need a large amount of leg, arm, and facial skin exposure, for about 15 minutes 4 times a week, to get the minimum.
Still not convinced?
Dr. David Feldman of Stanford University School of Medicine’s endocrinology division tells us that Vitamin D is now recognized to have expanded activity beyond its traditional role in prevention of osteoporosis, rickets, and osteomalacia. Recent evidence points to its role in the prevention of autoimmune diseases such as fibromyalgia (considered a muscle endurance problem in physical therapy), and the development of certain cancers.
Feldman correlates distance from the equator with the incidence of breast, colon, and prostate cancers. This is good information for boomers, and especially to those of us in Northern California. Adding some D to the diet could decrease the usual cancer risk associated with our lack of sunlight and advancing age. Vitamin D promotes natural cell death, a problem with self-perpetuating cancer cells, and blocks the blood supply development needed by growing cancer cells.
What’s the bottom line?
Wear your sunblock when enjoying outdoor activities, but do try to get 10 to 15 minutes of sun exposure several times per week. Get your blood level checked so that you know your baseline. Take the recommended daily supplement to ensure a good blood level. Be sure to take calcium; D doesn’t work alone. All dancers should take 1,200 to 1,500 milligrams of calcium per day, coupling it with magnesium for maximum absorption.
The take-home message is that we all want to keep dancing, and we have enough information to know how. A strong infrastructure, our skeleton, is our insurance to keep dancing into the sunset.
I have faith in you.