Evidence that increased calcium intake does not prevent early postmenopausal bone loss

Area of Science:

• Bone Metabolism and Endocrinology
• Postmenopausal Health
• Nutritional Science

Background:

• The role of calcium in preventing bone loss among early postmenopausal women remains debated.
• Previous research has yielded conflicting results regarding calcium's efficacy in bone health maintenance.

Purpose of the Study:

• To investigate the relationship between calcium intake and bone loss in early postmenopausal women.
• To determine if varying levels of calcium intake influence bone mineral density (BMD) and bone turnover markers.

Main Methods:

• Analysis of data from 394 women in the placebo group of the Early Postmenopausal Interventional Cohort study.
• Measurement of calcium intake, BMD (lumbar spine, total body, forearm, hip), and biochemical bone turnover markers over 24 months.
• Intervention included advising women with low baseline calcium intake (<500 mg/d) to increase consumption.

Main Results:

• Mean BMD decreased by approximately 1.9% at the lumbar spine and 1.6% at the hip over 24 months.
• No significant association was found between baseline or changed calcium intake and BMD or bone turnover markers.
• Even women in the highest tertile of calcium intake (>1333 mg/d) experienced BMD declines similar to those in lower intake groups.

Conclusions:

• Calcium intake alone, even when increased, did not demonstrate a protective effect against bone loss in this cohort.
• Significant declines in BMD occurred despite variations in calcium consumption.
• More potent therapeutic strategies are necessary to effectively increase or maintain BMD in early postmenopausal women.