Effect of Calcium Supplement Particle Size and Vitamin D Supplement on Calcium Retention in Adolescent Girls

Study Overview
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Brief Summary
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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.

Detailed Description
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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: 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. 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.

Official Title
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The Effect of Particle Size of Calcium Carbonate and Vitamin D on Calcium and Bone Parameters in Adolescent Girls

Conditions
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Osteoporosis

Intervention / Treatment
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* Dietary Supplement: Small Particle Size Calcium Carbonate Supplement
* Dietary Supplement: Large Particle Size Calcium Carbonate Supplement
* Dietary Supplement: Vitamin D
* Dietary Supplement: Calcium Placebo


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 12 Years
Maximum Age: 14 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Small Particle Size Calcium Carbonate<br>Subjects are given small particle size calcium carbonate supplement twice daily (total of 625 mg/d from supplement). | Dietary Supplement: Small Particle Size Calcium Carbonate Supplement<br>* Small Particle Size Calcium Carbonate - tablet, 325 mg/tablet. Given once or twice daily depending on study arm.<br>|
| Active Comparator: Large Particle Size Calcium Carbonate<br>Subjects are given a large particle size calcium carbonate supplement twice daily (total of 625 mg/d from supplement). | Dietary Supplement: Large Particle Size Calcium Carbonate Supplement<br>* Large Particle Size Calcium Carbonate Supplement - tablet, 325 mg/tablet. Given twice daily.<br>|
| Placebo Comparator: Calcium Placebo<br>Subjects are given two placebo tablets daily, which are identical to the large and small particle size calcium carbonate supplements. | Dietary Supplement: Calcium Placebo<br>* Placebo tablets identical to the large and small particle size calcium carbonate tablets. Given twice daily.<br>|
| Active Comparator: No Vitamin D supplement<br>Subjects are given calcium carbonate supplement once daily (325 mg/d from supplement). | Dietary Supplement: Small Particle Size Calcium Carbonate Supplement<br>* Small Particle Size Calcium Carbonate - tablet, 325 mg/tablet. Given once or twice daily depending on study arm.<br>|
| Experimental: Vitamin D supplement<br>Subjects are given a calcium supplement once daily (325 mg/d from supplement) with 1000 IU/d vitamin D supplement. | Dietary Supplement: Small Particle Size Calcium Carbonate Supplement<br>* Small Particle Size Calcium Carbonate - tablet, 325 mg/tablet. Given once or twice daily depending on study arm.<br>Dietary Supplement: Vitamin D<br>* Vitamin D - capsule, cholecalciferol, 1000 IU/tablet. Given once daily.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | 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 | 

Secondary Outcome Measures

| Outcome Measure | 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 | 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 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Calcium, Vitamin D, Particle Size, Adolescents, Bone, Osteoporosis