Going Crazy over Calcium

By Anastasia Toufexis

Just try to avoid calcium these days. The miracle mineral of the moment, it is being added to everything from baking flour to bread, from orange juice to Tab. Meanwhile, such familiar products as milk and yogurt, as well as Tums and Total cereal, are being touted for their high calcium content. And calcium supplements are flooding the market, with sales of liquids and pills surging from $18 million in 1980 to $240 million last year. Those who gag on the tablets, which are huge gullet pluggers, can even try getting their mineral boost in a novel way -- EZ-CAL Soft Calcium Whip, an aerosol can filled with calcium foam that was introduced in test markets last week. In short, just about anything consumable has been laced with the stuff.

The main propellant for the craze has been the presumption that calcium can ! help prevent osteoporosis, the degenerative bone disease that afflicts an estimated one-quarter of elderly men and half of elderly women in the U.S. Three years ago scientists at a National Institutes of Health conference on osteoporosis advised Americans to increase their daily intake of calcium to 1,000 mg (compared with the Government RDA of 800 mg); the recommended level for postmenopausal women was an even higher 1,500 mg. Calcium fever soon swept the country.

Last week researchers, concerned by the commercial hype, met once again at NIH headquarters in Bethesda, Md. While reiterating their earlier counsel on daily intake, they sought to "bring calcium down a peg or two," in the words of one, and to caution against unbridled enthusiasm. "Calcium is not a panacea for osteoporosis," declares Washington University's Dr. William Peck, who was a leader at both gatherings. "The ads promise more than calcium is going to deliver."

In fact, both the disease and calcium's role in bone development are still poorly understood. During normal youthful maturation the body readily absorbs calcium, which helps to build bigger and denser bones. After about age 35, however, the process begins to reverse. The body becomes less able to take in calcium, and the blood, which needs the mineral for other organs, begins to leach it out of bones, leaving them weaker. Women suffer in particular because their bones are smaller and less dense than men's. More important, for reasons that are not yet known, menopause speeds up bone loss. Osteoporosis is the excessive form of this natural process.

An extreme consequence is a bent frame and the so-called dowager's hump. In Cincinnati, retired Registered Nurse Daisy Randle Smith, 76, has a hump now, and despite wearing a brace, she has had spinal fractures in nine of the past ten years; one fracture was caused by a slight sneeze. "I'm in pain most of the time," she says, "and I've lost 5 1/2 inches since 1977." The loss of height is irreversible, as is the brittleness. Fractures like Smith's are common -- 1.2 million occur in the U.S. each year. Almost half are to spinal vertebrae, and one-fifth involve the hip. The effects can be devastating. Nearly one-fifth of those with hip fractures die within six months.

Calcium supplements, unfortunately, cannot prevent osteoporosis after menopause. At the Bethesda meeting, researchers reported on eight studies that found extra calcium had little or no effect in slowing bone loss, even / when the dosage was as high as 3,000 mg per day. The most effective defense against osteoporosis in these women, all agreed, is estrogen replacement. Such therapy has been linked in the past to an increase in endometrial cancer, but doctors now believe the risk can be minimized by tandem use of progesterone- like hormones.

What about calcium supplements before menopause? Scientists say the best hedge against osteoporosis is strong, dense bones formed during younger years. But a U.S. Public Health survey found that women from 18 to 44 get a daily average of calcium that ranges from 679 mg for the youngest group to 603 mg for the oldest. Some physicians contend that Americans can get necessary amounts by consuming more calcium-rich foods, especially milk and dairy products. Others, questioning whether women will change their diets sufficiently, see a need for pills and fortified foods. That raises the question of what scientists call bioavailability: How much of the mineral is in a form that the body can use? A cup of milk supplies 270 mg, while a 500-mg tablet of calcium carbonate provides just 200 mg. "The pharmaceutical industry is selling products on the basis of calcium content alone," says Dr. Robert Heaney of Omaha's Creighton University. "Sometimes that is sheer fraud."

Moreover, researchers point out, although calcium does help build bone and retain it, the mineral is simply one factor in lifelong skeletal health. Some studies have found bone loss is slower in those who engage in such weight-bearing physical activities as running and walking. In one survey, women ages 35 to 65 who took a 50-minute aerobics class three times a week lost only 2.5% of the density in their forearm bones, compared with 9.5% for women who did not exercise. "Osteoporosis is a total life-style problem," emphasizes Heaney. "You can't cure a bad life-style with a pill, and it's a terrible strategic mistake to encourage people to think you can. If I'm sitting all day, don't walk to work, don't carry loads or work in the garden on the weekend, I'm going to lose bone. You can give me all the calcium in the world, and it's not going to stop it."

With reporting by Barbara Dolan/Chicago and Dick Thompson/Washington