Adolescent Development, Bone Mineralization
Conditions
Keywords
calcium, bone, bone density, adolescence
Brief summary
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.
Detailed description
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.
Interventions
DIETARY_SUPPLEMENTBeverage 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_SUPPLEMENTBeverage 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.
Sponsors
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Purdue University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
11 Years to 15 Years
Healthy volunteers
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
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Calcium retention (mg/d) | Metabolic balance will be determined over a two week period on a controlled diet after equilibration for one week on the same diet. |
Secondary
| Measure | Time frame |
|---|---|
| Serial serum biochemistry profiles (PTH, 1,25 dihydroxy-vitamin D, calcium) | Six serial measurements in 10 hours after ingestion of a calcium load representing one third of the daily consumption |
Countries
United States
Outcome results
None listed