Osteoporosis
Conditions
Keywords
Calcium, Vitamin D, Particle Size, Adolescents, Bone, Osteoporosis
Brief summary
This study has two research arms: The purpose of the 1st is to determine if a smaller particle size calcium carbonate supplement (than that which is now commercially available) improves calcium absorption and retention in adolescents girls. The purpose of the 2nd is to determine if vitamin D supplementation improves calcium absorption and retention in adolescents girls.
Detailed description
An important strategy to reducing the risk for osteoporosis and fracture in later life is to optimize the development of peak bone mass during adolescence. Because calcium is the main mineral component of bone, maximizing calcium absorption and retention during adolescence is important to maximize peak bone mass. Our two research arms address two different mechanisms by which calcium absorption and retention may be increased: 1. We hypothesize that a smaller particle size calcium carbonate supplement (than that which is now commercially available) may be better absorbed and lead to higher calcium retention in adolescents. 2. We hypothesize that vitamin D supplementation will increased calcium absorption and retention in adolescents. Subjects will be assigned to one of the two research arms. 1)Small and large particle size calcium supplements or placebo or 2) calcium supplements with or without vitamin D supplements will be given to subjects during two 3-week study periods in which subjects live on-site. Calcium absorption will be measured by parathyroid hormone suppression after a calcium load and by stable calcium isotope in some subjects. Calcium retention will be measured by calcium intake minus calcium excretion.
Interventions
DIETARY_SUPPLEMENTSmall Particle Size Calcium Carbonate Supplement
Small Particle Size Calcium Carbonate - tablet, 325 mg/tablet. Given once or twice daily depending on study arm.
DIETARY_SUPPLEMENTLarge Particle Size Calcium Carbonate Supplement
Large Particle Size Calcium Carbonate Supplement - tablet, 325 mg/tablet. Given twice daily.
DIETARY_SUPPLEMENTVitamin D
Vitamin D - capsule, cholecalciferol, 1000 IU/tablet. Given once daily.
DIETARY_SUPPLEMENTCalcium Placebo
Placebo tablets identical to the large and small particle size calcium carbonate tablets. Given twice daily.
Sponsors
Purdue University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Eligibility
Sex/Gender
FEMALE
Age
12 Years to 14 Years
Healthy volunteers
Yes
Inclusion criteria
* 12-14 year old girls * Generally Healthy
Exclusion criteria
* History of alcohol, smoking, or non-prescription drug use * Malabsorptive disorders, bone, liver, or kidney disease that may affect calcium metabolism * Oral contraceptive use * Pregnancy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Calcium Balance | weeks 2,3 + 5,6 | Total calcium(Ca) retention will be calculated - Ca retention/d = Ca intake/d - Ca excretion/d (urine + feces) |
| Calcium Absorption | Day 15, 30 | — |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Serum parathyroid hormone suppression | Day 19, 40 | Serum PTH will be measured by a 2-site immunoassay |
| Serum 25-hydroxyvitamin D | Day 1, 20, 2, 41 | Serum 25-hydroxyvitamin Dwill be measured by LCMS |
| Urinary Calcium | Weeks 2,3 + 5,6 | Ca content of all 24 h urine collections will be measured by Atomic Absorption Spectrophotometry |
| Fecal Calcium | Weeks 2,3 + 5,6 | Ca content of all fecal collections will be measured by Atomic Absorption Spectrophotometry |
Countries
United States
Outcome results
None listed