Its not just calories that count.

Dancers tend to eat with an eye to calories. Yet a healthy diet includes the vitamins and minerals essential to bone strength, your immune system, and your overall vitality. Calcium, for instance, enables your muscles to contract efficiently, and iron combats fatigue. Eating enough of these key nutrients helps you stay energized and avoid injury.

Boning Up A broken bone can jeopardize a dancer's career. Calcium plays a key role in bone density, but it doesn't work alone--it "partners" with vitamin D, which helps your body absorb and deposit it, strengthening your bones.

Because dancers must stay on top of their weight, a smoothie made with a cup of skim or one percent milk can be a great source of vitamin D. Dancers should aim for four servings of calcium a day, particularly in their teens. Joy Bauer, nutritionist for New York City Ballet, suggests either an ounce of cheese, tofu, almonds, dark leafy green vegetables, fish oil, egg yolks, or calcium fortified foods four times a day. "If you don't eat calcium every time, don't panic, just consider taking a calcium supplement," says Bauer. Some doctors suggest Turns to up calcium intake, but remember, too much caffeine, or taking iron supplements simultaneously, interferes with calcium absorption.

Iron Works "Because young women are losing blood every month, they need to replace their iron to avoid anemia," says Dr. Richard Gibbs, physician for the San Francisco Ballet. Iron delivers oxygen to every working cell in the body, enabling the muscles to perform. Dancers need iron for brainpower, too, to remember choreography, cues, and corrections. "If you're tired, you can't train as hard or perform as well," says Bauer.

Fifteen to 18 milligrams of iron per day is ideal for dancers, and the most absorbable form is found in red meats, chicken, turkey, and eggs. If you're a vegetarian, try plant sources like beans, nuts, seeds, spinach, raisins, iron-fortified cereals, and barley, but the iron won't be as readily absorbable. "If you have a bowl of Cheerios for breakfast, mushroom barley soup at lunch, and trail mix in the afternoon, you're doing well," Bauer says.

To increase iron absorption, up your intake of vitamin C-rich foods. If you have a salad with tomato and a turkey burger, for example, the tomato in the salad helps you absorb the burger's iron content. You can also increase absorption by eating oranges. A multivitamin with iron can provide your daily requirement, but before taking an iron-only supplement, talk to a nutritionist--large doses of iron can be harmful.

Good Things in "3s" Recent research has uncovered other helpful elements, like Omega-3 oils, which are anti-inflammatory, and which some believe can help prevent muscle soreness. Omega-3s are found in salmon, herring, and sardines, and also in Omega-3 fortified eggs. If you like edamame (Japanese soy beans) you're in luck, and wheat germ, flax seeds, walnuts, and canola and fish oils are also great sources.

Anti Is Pro Like everyone, dancers need antioxidants, a term that covers several vitamins (C and E), minerals, and related elements that aid cell operation and protect from disease. The vitamin C version is found in berries, apples, plums, artichokes, and beans, while antioxidants with beta-carotene (which some researchers think can help prevent certain cancers) are in carrots, sweet potatoes, kale, butternut and winter squash, and red peppers.

Don't Cramp Up Everyone tells you to eat bananas if you want to prevent cramping. That's because they are rich in potassium, which helps promote muscle contraction. Potassium also regulates fluids and mineral balance in your cells. There's no set minimum requirement, but if you eat your fair share of, yes, bananas, potatoes, melons, and berries, you can help yourself avoid muscle cramps.

Eat Your Spinach Magnesium plays a role in muscle function too. Spinach, salmon, sunflower seeds, soybeans, peanuts, chickpeas, brown rice, and whole grains are magnesium-rich. "Try to get magnesium through food, as most multivitamins don't have the daily 100 percent requirement," says Bauer.

Gibbs notes that very slim dancers often need to take supplements, but believes in moderation. "Taking a one-a-day vitamin should do the trick," he says.

Nancy Alfaro is a former dancer who writes and lives in New York.