Official Title: “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.

Study Type: Interventional

Study Design: Prevention, Randomized, Double Blind (Subject, Caregiver, Outcomes Assessor), Crossover Assignment, Efficacy Study

Study Primary Completion Date: August 2005

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.

Intervention(s) in this Clinical Trial

• Dietary Supplement: Beverage containing calcium citrate malate
  • Beverages containing a lower amount of calcium (0-400 mg/d) will be supplemented to a basal diet containing 600 mg/d Ca. The controlled diet will be consumed for 21 consecutive days.
• Dietary Supplement: Beverage fortified with calcium citrate malate
  • Beverages containing a higher amount of calcium (500-1300 mg/d) will be supplemented to a basal diet containing 600 mg/d Ca. The controlled diet will be consumed for 21 consecutive days.

Arms, Groups and Cohorts in this Clinical Trial

• Experimental: B
  • Supplementation of a higher level of calcium (500-1300 mg/d) via calcium fortified beverages to a basal diet of 600 mg/d for 21 consecutive days. All excreta will be collected.
• Experimental: A
  • Supplementation of a lower level of calcium (0-400 mg/d) via calcium fortified beverages to a basal diet of 600 mg/d for 21 consecutive days. All excreta will be collected.

Primary Measures

• Calcium retention (mg/d)
  • Time Frame: Metabolic balance will be determined over a two week period on a controlled diet after equilibration for one week on the same diet.
    Safety Issue?: No

Secondary Measures

• Serial serum biochemistry profiles (PTH, 1,25 dihydroxy-vitamin D, calcium)
  • Time Frame: Six serial measurements in 10 hours after ingestion of a calcium load representing one third of the daily consumption
    Safety Issue?: No

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

Gender Eligibility for this Clinical Trial: Both

Minimum Age for this Clinical Trial: 11 Years

Maximum Age for this Clinical Trial: 15 Years

Are Healthy Volunteers Accepted for this Clinical Trial?: No

Lead Sponsor: Purdue University

Overall Clinical Trial Officials and Contacts

Connie Weaver, PhD Principal Investigator Department of Foods and Nutrition, Purdue University  

Information obtained from ClinicalTrials.gov on July 02, 2009

Link to the current ClinicalTrials.gov record. http://clinicaltrials.gov/show/NCT00591708

Study ID Number: AR40553

ClinicalTrials.gov Identifier: NCT00591708

Health Authority: United States: Institutional Review Board