The proposed rule allows food and beverage manufacturers to include new information on the label and in the meantime eliminate some other information which is no longer justified.

The claim on calcium for its preventative role in osteoporosis was authorized in 1993, according to the FDA. The new rule amends the existing health claim by allowing claims on both calcium and vitamin D for their potential preventative effect against osteoporosis.

In addition, the proposed rule shortens the existing claim language by eliminating the reference to sex, race, and age as the benefits apply to both sexes, at all ages and race categories.  

Also the new role would drop "the need to identify the mechanism by which calcium reduces the risk of osteoporosis and the requirement that the claim state that there are limits to benefit of calcium intakes above 200% of the Daily value," the FDA states in its announcement on Friday.

The proposal is a response to a health claim petition submitted by the Beverage Institute for Health and Wellness, the Coca-Cola Company.   The FDA bases its decision on its review of the publicly available scientific evidence including the 2004 Surgeon General's report on Bone Health and Osteoporosis and the 2000 NIH Consensus Statement on Osteoporosis, Prevention, Diagnosis and Therapy.

While calcium and vitamin D play an important role in maintaining bone health in adults, a few issues need to be addressed, said a scientist affiliated with foodconsumer.org. For instance, supplementation of calcium and vitamin D may not be as important in children as in adults.   Healthy children who eat a healthy diet and follow a healthy lifestyle rarely need supplements of vitamin D and calcium although supplementation and fortification of calcium and vitamin D may help certain children, according to a review article.

Calcium and vitamin D supplements do not benefit all the adults.  A  study published in 2005 in the Lancet finds that supplementation of vitamin D, calcium, or both, does not lower the risk of secondary bone fracture from osteoporosis in the elderly who have had one incident of bone fracture.

Elderly people who are frail and at risk for bone fractures may be helped somewhat by giving them both vitamin D and calcium. But the benefits may be marginal and appear only to help those who live in nursing homes or other institutions, according to Alison Avenell, M.D., of the University of Aberdeen, Scotland, and her colleagues who published their review of 38 randomized or quasi-randomized trials in the July 2005 issue of issue of The Cochrane Library.

Potential problems exist for uncontrolled intake of calcium and vitamin D.   Too much of calcium in the blood (hypercalcemia) has been associated with use of calcium supplementation. Mild hypercalcemia may not result in any symptom, or cause loss of appetite, nausea, vomiting, constipation and dry mouth, thirst and frequent urination.   A severe condition could cause confusion, delirium, coma, and if not treated, death, according to the Linus Pauling Institute.

High levels of vitamin D in the blood (hypervitaminosis D) are also toxic as it induces abnormally high serum calcium levels (hypercalcemia).

To prevent osteoporosis, two things may be equally important, experts say.   One is to obtain the peak bone mass during childhood and young adulthood and the other is to maintain the bone health later in life by following a healthy diet and lifestyle.

For children, doing lots of physical exercise, particularly those weight bearing activities such as jumping, and getting exposed to lots of sunshine, and using a well-balanced diet with limited amounts of meat and dairy and unlimited fruits and vegetables may be the best recipe to obtain the best peak bone mass.

Similarly for adults, doing routine physical exercise and eating a diet that can keep the body pH normal would likely prevent loss of bone minerals such as calcium.

Taking calcium and vitamin D supplements alone may not work as well as expected to help prevent osteoporosis.   Other dietary elements have proved important as well.   For instance, high protein intake may cause calcium loss and raise risk of osteoporosis.   Americans consume an average amount of protein that is equivalent to 15% of their daily energy intake - 5 % more than the recommended amount.

On the other hand, use of potassium citrate or similar salts can help protect bone health, according to a study published a study published in the November issue of The Journal of The American Society of Nephrology.   Vitamin 12 seems to be also helpful, according to the Framingham Osteoporosis Study. This is particularly important to those who do not eat meat and dairy as the vitamin does not exist in plant foods.