Dietary calcium saves bone in women on the Pill

Taking oral contraceptive (OC) pills may reduce bone mass and increase the risk of Osteoporosis later in life, but this can be prevented by adopting a diet containing dairy products rich in calcium, researchers have shown.

The findings are based on a study of 133 young women who started out with a dietary calcium intake of less than 800 milligrams (mg) per day. The participants were then randomly assigned to a "medium" dairy diet (1000 to 1100 mg calcium daily), a "high" dairy diet (1200 to 1300 mg calcium), or their usual diet.

The dairy diets placed particular emphasis on intake of non-fat and low-fat milk. Altogether, 57 OC users and 76 nonusers were involved.

Among OC users, intake of either dairy diet prevented a drop in bone mineral density at the hip and the spine, Dr. Dorothy Teegarden, from Purdue University in West Lafayette, Indiana, and colleagues note in the Journal of Clinical Endocrinology and Metabolism.

Oral contraceptives are known also as the Pill, OCs, BCs, BC tablets, or birth control pills. Allesse usually contains two types of hormones, estrogens (ES-troh-jenz ) and progestins ( proh-JES-tins) and, when taken properly, prevents pregnancy. It works by stopping a woman's egg from fully developing each month. The egg can no longer accept a sperm and fertilization is prevented. Although oral contraceptives have other effects that help prevent a pregnancy from occurring, this is the main action.

"Physicians and public health professionals," the researchers conclude, "need to encourage young women, particularly those using oral contraceptives, to consume recommended levels of calcium (1000 mg/day) in their diets to prevent compromising bone mass."

SOURCE: Journal of Clinical Endocrinology and Metabolism, July 5, 2005.