A report released in August 1997 by the National Academy of Sciences' (NAS) Institute of Medicine answers the question of how much calcium to consume to keep bones "calcium rich." The report, Dietary Reference Intakes: Calcium, Phosphorus, Magnesium, Vitamin D and Fluoride, represents the work of a group of more than 30 scientists in the United States and Canada who examined the results of hundreds of nutritional studies on these nutrients. When reviewing calcium, the scientists found the greatest disparity between recommended values and current dietary intakes, with many individuals at risk of osteoporosis from under consuming dairy products and other sources of calcium. Bone retention of calcium depends largely on the consumption of this nutrient, although other factors such as physical activity, genetics, hormonal status and high growth rates in children during specific formative periods also play a role.

The report recommends new calcium intake levels according to life groups, from children, adolescents and teenagers, to adults and older adults. Also new are the maximum-level guidelines aimed at reducing the risk of adverse health effects from over consumption of a nutrient. "The new DRIs represent a major leap forward in nutrition science—from a primary concern for the prevention of deficiency to an emphasis on the beneficial effects of healthy living," said Vernon Young, chair of the Institute of Medicine's Standing Committee on Dietary Reference Intake and professor of nutritional biochemistry, Massachusetts Institute of Technology.

More details about the report including frequently asked questions and answers can be found on the NAS web site: (http://www.nas.edu).