If you're anywhere from 19 to 24 years old, you need more calcium in your diet than the experts recommended up to a few weeks ago.
And whatever your age, you're probably not getting as much calcium as you need.The mineral is the most abundant in the human body, making up almost 2 percent of it by weight. The calcium balance in cells is so finely tuned and fiercely protected that the body will rob the bones to get it if there's not enough in the diet.
While bones are adding mass, the dietary need is even greater. A body chronically shortchanged on calcium throughout youth and adulthood is a prime candidate for osteoporosis, or abnormal loss of bone tissue, in later years.
In recent years scientists have come to understand that bones continue forming later into adulthood than previously believed. That led a National Research Council committee last month to raise the age at which elevated calcium intake is recommended.
Previously, children from age 11 to age 18 were directed to consume 1,200 milligrams of calcium daily, compared to 800 milligrams for other ages. The larger figure is about the equivalent of four cups of skim milk, or 4.5 ounces of Swiss cheese, or three chocolate milkshakes.
Scientists now realize that bone formation continues well into the 20s, giving rise to the change in the Recommended Dietary Allowance.
Not everyone who fails to meet the calcium recommendation will develop osteoporosis, of course. But Agriculture Department annual food consumption figures indicate most Americans don't get the calcium they need.
The 1985 survey, for example, found that fewer than a quarter of all women - the sex more susceptible to osteoporosis - attained or surpassed the calcium RDA. White women on average were consuming just three fourths of the calcium needed; black women a bit more than half.
Such deficits are surprising, because calcium is readily found in dairy products.