Calcium Metabolism in Asian Adolescents

Calcium Metabolism in Asian Adolescents

Maximizing calcium retention by the skeleton within the genetic potential is a key strategy to prevent osteoporosis. It has been shown that calcium retention varies between blacks and whites and between gender within race. This study is designed to study the relationship between calcium intakes and calcium retention in Asian adolescent girls and boys. It is hypothesized that calcium intakes which maximize calcium retention will be lower in Asians than for whites studies under the same conditions. In addition it is thought that the differences between races in the physiological mechanisms involved in calcium metabolism will result in a lower calcium intake required to observe a plateau in calcium retention. This is turn could be translated into lower calcium requirements in Asians relative to Caucasians for achieving optimal peak bone mass.

Adolescent Asian boys and girls will consume a controlled diet for two three-week periods. The basal diet will contain 600 mg/d calcium and will be supplemented with beverages fortified with calcium citrate malate to achieve a range of intakes from 600-2100 mg Ca/d. Each participant will be studied on one of four combinations of a lower and a higher calcium intake within that range in a cross-over design.

Inclusion Criteria:

• healthy teens of Asian descent

Exclusion Criteria:

• malabsorptive disorders
• anemia
• smoking, illegal drugs
• oral contraceptives
• pregnancy
• drugs that influence calcium metabolism
• body weight for height greater than 85 percentile