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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.
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:
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.
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Small Particle Size Calcium Carbonate | Experimental | Subjects are given small particle size calcium carbonate supplement twice daily (total of 625 mg/d from supplement). |
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| Large Particle Size Calcium Carbonate | Active Comparator | Subjects are given a large particle size calcium carbonate supplement twice daily (total of 625 mg/d from supplement). |
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| Calcium Placebo | Placebo Comparator | Subjects are given two placebo tablets daily, which are identical to the large and small particle size calcium carbonate supplements. |
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| No Vitamin D supplement | Active Comparator | Subjects are given calcium carbonate supplement once daily (325 mg/d from supplement). |
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| Vitamin D supplement | Experimental | Subjects are given a calcium supplement once daily (325 mg/d from supplement) with 1000 IU/d vitamin D supplement. |
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Small Particle Size Calcium Carbonate Supplement | Dietary Supplement | Small Particle Size Calcium Carbonate - tablet, 325 mg/tablet. Given once or twice daily depending on study arm. |
| Measure | Description | Time Frame |
|---|---|---|
| Calcium Balance | Total calcium(Ca) retention will be calculated - Ca retention/d = Ca intake/d - Ca excretion/d (urine + feces) | weeks 2,3 + 5,6 |
| Calcium Absorption | Day 15, 30 |
| Measure | Description | Time Frame |
|---|---|---|
| Serum parathyroid hormone suppression | Serum PTH will be measured by a 2-site immunoassay | Day 19, 40 |
| Serum 25-hydroxyvitamin D | Serum 25-hydroxyvitamin Dwill be measured by LCMS |
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Inclusion Criteria:
Exclusion Criteria:
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| Name | Affiliation | Role |
|---|---|---|
| Connie M Weaver, PhD | Purdue University | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Purdue University | West Lafayette | Indiana | 47906 | United States |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 20962148 | Derived | Park CY, Hill KM, Elble AE, Martin BR, DiMeglio LA, Peacock M, McCabe GP, Weaver CM. Daily supplementation with 25 mug cholecalciferol does not increase calcium absorption or skeletal retention in adolescent girls with low serum 25-hydroxyvitamin D. J Nutr. 2010 Dec;140(12):2139-44. doi: 10.3945/jn.110.124891. Epub 2010 Oct 20. |
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| Large Particle Size Calcium Carbonate Supplement | Dietary Supplement | Large Particle Size Calcium Carbonate Supplement - tablet, 325 mg/tablet. Given twice daily. |
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| Vitamin D | Dietary Supplement | Vitamin D - capsule, cholecalciferol, 1000 IU/tablet. Given once daily. |
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| Calcium Placebo | Dietary Supplement | Placebo tablets identical to the large and small particle size calcium carbonate tablets. Given twice daily. |
|
| Day 1, 20, 2, 41 |
| Urinary Calcium | Ca content of all 24 h urine collections will be measured by Atomic Absorption Spectrophotometry | Weeks 2,3 + 5,6 |
| Fecal Calcium | Ca content of all fecal collections will be measured by Atomic Absorption Spectrophotometry | Weeks 2,3 + 5,6 |
| ID | Term |
|---|---|
| D010024 | Osteoporosis |
| ID | Term |
|---|---|
| D001851 | Bone Diseases, Metabolic |
| D001847 | Bone Diseases |
| D009140 | Musculoskeletal Diseases |
| D008659 | Metabolic Diseases |
| D009750 | Nutritional and Metabolic Diseases |
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| ID | Term |
|---|---|
| D014807 | Vitamin D |
| ID | Term |
|---|---|
| D012632 | Secosteroids |
| D013256 | Steroids |
| D000072473 | Fused-Ring Compounds |
| D011083 | Polycyclic Compounds |
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