WASHINGTON -- You bypass the grocery dairy aisle, shun broccoli and greens, skip the calcium-fortified orange juice. Wonder if your bones are weak?
Americans are facing what experts say is a dire shortage of calcium in their diets. It starts in childhood, when kids quickly learn to guzzle colas or sugar-filled "fruit drinks" instead of milk -- one aghast nutritionist even spotted baby bottles sporting soft-drink logos.
Calcium's claim to fame is building strong bones and teeth. But this versatile mineral also may play other important roles, such as lowering blood pressure or preventing colon cancer.
Yet three out of four Americans are thought to eat too little calcium.
"It doesn't matter who you are -- we are not ingesting enough calcium from childhood up," said University of Colorado nutrition professor Susan Johnson.
"The United States needs a national, comprehensive plan to improve the calcium nutrition of our people," Dr. Robert Heaney of Creighton University told fellow calcium specialists at a meeting last week to discuss how to do that.
The government is launching two new campaigns to boost calcium consumption by children and teen-agers -- the ages bone builds fastest -- but key to increasing calcium consumption is understanding why it's important and what foods have it.
When you don't eat enough calcium, the body leaches the mineral from your bones, weakening them over time. Ten million Americans, mostly women, already have osteoporosis, where their bones are so brittle they snap.
But research suggests calcium's benefit may extend far beyond bones, Heaney said. Calcium-poor diets seem to increase risk of high blood pressure. Increasing dietary calcium in patients prone to colon cancer significantly cut their risk of tumors. Calcium even seemed to cut in half symptoms of premenstrual syndrome.
How much calcium do you need? The Institute of Medicine set 1,000 milligrams a day as an adequate level for most adults. Teen-agers need more, 1,300 milligrams, because their bones are growing so fast.
Need varies for other ages -- 500 milligrams a day for toddlers; 800 milligrams for 4- to 8-year-olds; and 1,200 milligrams for people over age 50.
Overall, dairy products like yogurt, milk and cheddar cheese pack the most calcium. For most children, a few glasses of milk a day would meet the need.
Your child only likes chocolate milk? No problem. Chocolate, skim, low-fat or regular, the calcium's the same, about 300 milligrams.
But there are many other choices. Calcium-fortified orange juice packs as much calcium per glass as milk.
Other sources may not have as much calcium as dairy, but can add up: Dark leafy vegetables, broccoli, soybeans, canned salmon.
You may be sneaking in calcium without knowing it: A slice of cheese pizza, for instance, has 220 milligrams. Two tablespoons of blackstrap molasses has about 270. A handful of almonds has 100.
To help parents understand exactly how much their children need at each age -- and what foods to choose -- the government is offering a free booklet as part of calcium campaign called "Milk Matters." To get the booklet, call 1-800-370-2943.
And the U.S. Public Health Service is about to launch a special bone health campaign aimed at increasing teen-age girls' calcium consumption.
Calcium supplements can help, too, but experts agree that calcium from food is best because calcium-rich foods also pack other vital nutrients.
Use supplements to "top off an otherwise good diet," Heaney advises. "They're not a substitute for good eating."
What if you have trouble digesting lactose, or milk sugar? It's a problem for millions of Americans, especially minorities.
Aside from non-dairy calcium sources, lactose-free milk and tablets that aid in milk digestion are widely sold. Calcium-rich hard cheeses contain little lactose. But studies show many lactose-intolerant people can digest some milk as long as they drink it with meals, said Dr. Duane Alexander of the National Institutes of Health.
But calcium alone isn't enough. Adequate vitamin D -- from the sun, certain foods like milk or cereal, or supplements -- helps the body absorb calcium. High-protein diets, in contrast, can inhibit calcium absorption.
--Plain fat-free yogurt, one cup: 400 milligrams.
--Sardines, 3 ounces: 370 mg.
--Milk, 8 ounces: 300 mg.
--Calcium-fortified orange juice: 300 mg.
--Collard greens, 1 cup cooked: 300 mg.
--Cheddar cheese, 1 ounces, or ricotta cheese, one-half cup: 300 mg.
--Cheese pizza, one slice: 220 mg.
--Oysters, raw, 1 cup: 220 mg.
--Ice cream or frozen yogurt, 1 cup: 200 mg.
--Canned pink salmon, 3 ounces: 200 mg.
--Macaroni & cheese, one-half cup: 180 mg.
--Soybeans, one-half cup cooked: 130 mg.
--Broccoli, cooked or raw, 1 cup: 118 mg.
--Almonds, one-fourth cup: 100 mg.
--Calcium-added tofu: amounts vary greatly, from 220-400 mg, so check product label.
Source: National Institutes of Health.