Research shows regular adequate intake of calcium and exercise can strengthen the bones, but many people do not know whether they are getting enough calcium in their diets, researchers at the German Institute for Quality and Efficiency in Health Care said.

The World Health Organization recommends a minimum daily intake of calcium of 1,300 mg for women after menopause and men age 65 and older. The institute developed an online calculator for its Web site at www.informedhealthonline.org with the help of the Robert Koch Institute in Berlin.

The calculator helps a person estimate roughly how much calcium they are getting through their diet every day and whether it is enough.

If a person cannot get enough calcium in their diet, calcium supplements can help -- trials have shown that taking daily calcium supplements can help protect people who are at high risk of bone fracture, said Peter Sawicki, director of the institute.

"Even when you are already over age 70, you can reduce your risk of bone fracture if you get enough calcium," Sawicki said in a statement.