About 75 percent of Americans do not meet their daily dietary needs for calcium. Unfortunately, most of us do not suffer from the consequences of this nutrient deficiency until we are older. Calcium has many functions in the body, including vital roles in muscle contraction and the firing of nerves. Calcium is also involved in the formation of healthy bones and teeth. If the diet is deficient in calcium, the body takes what it needs to carry out these vital functions from the bones. Over time, this process causes the bones to weaken and become brittle and eventually fracture. The bones most affected by this are in the hip and the vertebrae. This bone thinning disease is known as osteoporosis. This disease affects 25 million Americans and costs our health care system over $10 billion annually. Risk factors for developing osteoporosis include: family history of the disease, slight body build, female gender, excessive alcohol consumption, cigarette smoking, and inadequate vitamin D and calcium intake.

Running, as well as other weight bearing exercises, lowers the risk of acquiring osteoporosis. Exercise stimulates the remodeling of bones and thus strengthens them. However, if a runner's diet is inadequate in calcium, another problem may arise. The risk of acquiring stress fractures greatly increases with inadequate dietary intake of calcium. This risk is even greater in a female runner who is not menstruating (amenorrheic). All of the female runners I have worked with who had stress fractures were not consuming enough calcium in their diet. To decrease the risk of acquiring stress fractures and developing osteoporosis, you must meet your daily dietary calcium needs. Below is a chart listing daily calcium requirements. Calcium Requirements* Age Group Adequate Intake(mg of Calcium) 9 - 18 years 1,300 19 - 50 years 1,000 50+ years 1,200

*Source: National Academy of Sciences, 1997

Which Is Better, Food Or A Supplement? The best source of calcium for the body is found in food, particularly dairy products. Dairy products also contain vitamin D, which increases the absorption of calcium. Consuming dairy products is the easiest way to meet calcium needs because they contain lots of calcium and you need less of them to meet your daily needs compared to other foods. A supplement is warranted if you do not meet your needs through your diet. Calcium supplements come in a capsule or in chewable form. Most supplements are 500 mg and, if you are consuming more than one a day, take them separately to increase the absorption of the calcium.

Below is a list of foods and their calcium content. This year make it a priority to meet your calcium needs.

Food and serving size Calcium content (mg) Lowfat yogurt with fruit, 1 cup 345 Skim milk, 1 cup 302 2% milk, 1 cup 297 Ice milk, 1 cup 274 Tofu, firm, 1/2 cup 258 Frozen yogurt, 1 cup 240 Mozzarella cheese, 1 oz 207 Cheddar cheese, 1 oz 204 Salmon, canned with bones, 3 1/2 ounces 185 Cottage cheese, 1 cup 155 Spinach, cooked, 1/2 cup 138 Almonds, 1/4 cup 92 Mustard greens, 1/2 cup 52 Broccoli, 1/2 cup 36