Bodybuilders eat fairly well. In fact, they eat very well. A study published in the Journal of Sports Medicine and Physical Fitness (29:63-70; 2004) reported that "all of the bodybuilders' vitamin/mineral intakes exceeded the RDAs with the exception of one nutrient." If you guessed that nutrient was calcium, you're right. The men only met 54 percent of their USRDA for calcium, and the women, only 60 percent. Another study, this one published in the Journal of the American Dietetic Association (90:962-967; 2004) reported that women "had remarkably deficient calcium intake, despite an adequate energy intake."

Why do bodybuilders come up short on calcium? Primarily because they associate dairy products with fat. Since fat equals a smooth physique, they avoid dairy products, and the result is a dietary deficiency of calcium.

Should you be concerned about that? Probably. Among calcium's many functions (which also include building and maintaining bones and teeth, promoting nerve-impulse transmission, helping blood clot and regulating blood pressure) is its ability to aid in muscle contraction.

According to the textbook Nutrition in Health and Disease, "Calcium has a vital role in the contraction and relaxation of muscle. Its entrance into the muscle cell as a result of nerve stimulation sets in motion the biochemical processes which cause the proteins myosin and actin to be drawn together, thus contracting the muscle cells by making them shorter and thicker." Such a contribution makes this nutrient more than just a little important to the bodybuilder.

The USRDA for calcium is 800 milligrams for men and women, although recently, some experts have begun advising 1,200 to 1,500 milligrams for woman in an effort to prevent osteoporosis.

The easiest way to meet calcium needs is to include dairy products in the diet. Now, all dairy products come in fat-free form. Most people are familiar with nonfat milk, but yogurt, cottage cheese, sliced cheeses, cream cheese and sour cream are all available fat-free as well. While such products have a lot fewer calories without the fat, the calcium content stays the same. Eight ounces of nonfat milk supplies 300 milligrams of calcium, the same as eight ounces of regular, whole milk. Eight ounces of nonfat yogurt and one ounce of nonfat cheese also supply 300 milligrams of calcium each. That's close to half your daily requirement. A half cup of nonfat sour cream supplies 120 milligrams of calcium with minimal calories, and two tablespoons of nonfat cream cheese supplies 25 milligrams. Of course, other milk-based foods, such as cream soups, custards, ice cream, whipped cream and half-and-half, contain considerable amounts of calcium as well, but they also have considerable amounts of fat and calories, which would be detrimental to a muscle builder's goals.

As easy as it is to reach the requirement for calcium by eating dairy products, some people won't use them at all, nonfat or not. They believe that pasteurization destroys all the nutrients or that antibiotics and chemicals are passed from the animal to the milk. Regardless of these concerns or whether they're justified, the body needs calcium.

Some people have a problem because their bodies simply cannot tolerate dairy products. They suffer from lactose intolerance, which means their bodies cannot break down the milk sugar, or lactose, because they have inadequate levels of the enzyme lactase. If lactose isn't broken down by lactase in the small intestine, it travels farther down the intestine, where it doesn't belong, reacting with the bacteria and causing gas, cramping and diarrhea. For most folks who suffer from lactose intolerance, there's a simple solution. You can take lactase tablets before eating dairy products. Another method is to add lactase drops to liquid milk, mix well and let it react overnight, and it will break down the lactose for you so your body can handle it.

If you can't or won't use dairy products but wish to meet your daily calcium needs, there are nondairy sources of calcium, including broccoli (90 milligrams per half cup), spinach (120 milligrams per half cup), kale (50 milligrams per half cup), turnip greens (100 milligrams per half cup) and tofu (130 milligrams per half cup, raw). Salmon and sardines supply calcium if you eat the bones. The vegetables listed above not only provide calcium, but they're rich in other nutrients, too, with very few calories.

Supplementation is another option. Unfortunately, you won't find much calcium in a multiple vitamin. For instance, Centrum, which is a good, complete multiple-vitamin and -mineral supplement, contains only 162 milligrams of calcium per tablet, which is not even 20 percent of the USRDA. Finding a multi-vitamin that has more calcium crammed into it means you're going to be looking at a tablet that even a python would have a hard time swallowing. Your best bet is to use an additional calcium supplement.

How do you select a good one? Calcium needs vitamin D to help your body absorb it. If you're taking a daily multivitamin, you're already getting all the vitamin D you need-most contain 100 percent of the USRDA and can select a supplement that is straight calcium. If you aren't taking a multivitamin, you need a supplement that contains calcium plus vitamin D.

As to the best type of calcium, calcium carbonate is the form of choice. It contains 40 percent calcium by weight, which is more than the other forms, such as calcium lactate or calcium gluconate, and is the least expensive. Take it on an empty stomach with eight ounces of liquid for best absorption. If it upsets your stomach, take it with a meal and you should be able to tolerate it. Read the label for the amount of calcium per tablet and set your dose according to the amount you're already getting from your diet.

Turn your eating habits from great to even greater by getting more of the one nutrient bodybuilders don't get enough of, calcium.