Think of calcium as insurance for healthy bones

May 26, 1998|By Lynn F. Little

Think of your bones as a retirement account. The more calcium you stash in them when you are young, the better they will serve you in old age.

Calcium is well recognized for its importance in developing and maintaining a strong bone mass. Although adult stature is reached in the teen years, the skeleton continues to accumulate mass until age 30, at least as long as the diet supplies sufficient calcium. After that, bone mass remains fairly constant for several years, then begins to decline as aging sets in. For women, hormonal changes at menopause trigger bone-mass loss. In men, losses tend to become apparent somewhat later, around the age of 65.

Although a number of factors are important contributors to bone health, including genetics and adequate weight-bearing exercise, a key factor is getting enough calcium and vitamin D in the diet throughout the life span. Calcium builds bones and keeps them dense, while vitamin D enables the body to absorb and utilize calcium and adapt if calcium intake is too low. On the average, American women consume 500 to 600 milligrams of calcium daily. That is well below the recommended daily consumption of 1,000 to 1,200 milligrams. National Institute of Health recommends 1,000 to 1,500 milligrams as an "optimal" daily intake to maximize peak adult mass, maintain adult bone and minimize bone loss in later years.


For children ages 6 to 10, NIH recommends 800 to 1,200 milligrams of calcium daily. For adolescents and young adults through age 25, it recommends 1,200 to 1,500 milligrams. In the adult years between ages 25 and 65, 1,000 milligrams per day are recommended for men, pre-menopausal women and postmenopausal women on estrogen. For postmenopausal women not on estrogen and all men and women older than the age of 65, NIH recommends a daily intake of 1,500 milligrams of calcium to help slow bone loss.

In making these recommendations, NIH urges Americans to look to food first for their calcium. Food sources of calcium tend to supply other nutrients, such as phosphorous, vitamin D and lactose, which help the body absorb or use calcium.

Dairy products (milk, cheese, yogurt, etc.) are the most concentrated food sources of calcium. One cup of milk contains approximately 300 milligrams of calcium; one cup of plain yogurt around 400 milligrams. Even individuals who are lactose intolerant often can enjoy small amounts of such dairy products as yogurt, cheese and lactose-treated milk. Those who must avoid dairy products due to allergies or severe lactose intolerance still can consume significant amounts of calcium from dry beans, fish with edible bones, tofu (if processed with calcium sulfate), calcium-fortified orange juice and dark-green vegetables such as broccoli, kale, Chinese cabbage, collards and other greens.

For those unable to obtain sufficient calcium through diet, supplements such as calcium carbonate, calcium citrate, calcium lactate or calcium gluconate can help. Of these, calcium carbonate and calcium citrate most often are recommended because they are more readily absorbed and fewer pills are needed. Calcium citrate has the advantage of being somewhat easier for older people with low stomach acidity to tolerate. Calcium carbonate should be taken with meals and calcium citrate may be absorbed on an empty stomach. Look for labels that state the supplement meets USP standards or has passed a 30-minute dissolution test. Avoid supplements made with bone meal or dolomite; they may be contaminated with lead. Antacids made from calcium carbonate are an inexpensive but effective source of dietary calcium, as well.

Finally, don't pay more for claims of "natural" or sugar-free or starch-free formulas. According to a study conducted by Consumer Reports, calcium is calcium. Even chewable calcium tablets, though sometimes quite large, don't have a significant number of calories in their sugar and flavorings.

Maryland Cooperative Extension Service's programs are open to all citizens without regard to race, color, sex, disability, age, religion or national origin.

Lynn F. Little is a family and consumer sciences extension educator for University of Maryland Cooperative Extension Service.

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