Amorphous Calcium Carbonate (Acc) Versus Crystalline Calcium Carbonate (Ccc) Using Stable Calcium Isotopes In Postmenopausal Women

Study Overview
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Brief Summary
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The study objective is, to evaluate the fractional absorption of calcium from amorphous calcium carbonate (ACC) Vs crystalline calcium carbonate (CCC) dietary supplements in postmenopausal women.

Detailed Description
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This is a randomized, double-blind, crossover bioavailability study comparing the fractional absorption of calcium from amorphous calcium carbonate (ACC) versus crystalline calcium carbonate (CCC) using stable calcium isotopes in postmenopausal women. The study is comprised of 15 subjects orally administered immediately after breakfast a 600 mg gelatin capsules containing either 600 mg (2 capsules of 300 mg)of ACC (192 mg elemental calcium) of 480 mg CCC (192 mg elemental calcium), labeled with 15 mg of 44Ca (2 capsules of 300 mg). Five minutes following the oral administration, each subject will be infused intravenously with 1.5 mg of CaCl2 labeled with 42Ca over 10 min. Over the following 24 h subjects will consume meals that will be selected by the Unit of Clinical Nutrition at Sourasky Medical Center nutritionist on the basis of their food diary and ALL urine excreted during this time should be collected in a designated urine container and returned to the Unit of Clinical Nutrition at Sourasky Medical Center for evaluation. The same protocol as in day 0 with a crossover oral treatment will be performed after 21 day washout period. Dosing day will be designated Day 0. Eligible subjects are randomly assigned to one of the study treatments according to the following regimens:

Official Title
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A Randomised, Double-Blind, Crossover Bioavailability Study Comparing Amorphous Calcium Carbonate (Acc) Versus Crystalline Calcium Carbonate (Ccc) Using Stable Calcium Isotopes In Postmenopausal Women

Conditions
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Postmenopause

Intervention / Treatment
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* Other: CCC
* Other: ACC


Participation Criteria
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Eligibility Criteria
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INCLUSION CRITERIA • Absence of menstrual period for 12 months but not more than 5 years, or absence of menstrual period for 6 to 12 months and follicle stimulating factor (FSH) greater than 40 IU/L BMI 18-29 (inclusive) Subjects able to adhere to the visit schedule and protocol requirements and be available to complete the study. Subjects who provide written informed consent to participate in the study. EXCLUSION CRITERIA Women who, on the basis of a food frequency questionnaire, have an estimated daily calcium intake >1100 mg through combined diet (both supplements and food). Women with vitamin D deficiency < 30 ng/ml Women with hypercalcemia, nephrolithiasis, inflammatory bowel disease, malabsorption, chronic diarrhea, use of antibiotics within the past month, Woman suffering from digestive, hepatic, renal, or inflammatory diseases. Women who take oral steroids, anticonvulsants, bisphosphonates, estrogen compounds, calcitonin, or teriparatide within the past 6 months. Any acute medical situation (e.g. acute infection) within 48 hours of study start, which is considered of significance by the Principal Investigator (PI). Subjects who are non-cooperative or unwilling to sign consent form.

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 65 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: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: CCC<br>Crystalline calcium carbonate (CCC) | Other: CCC<br>* 600 mg (2 capsules of 300 mg) for oral use of 480 mg CCC (192 mg elemental calcium) intrinsically labeled with 15 mg 44Ca and 120 mg of inactive filler, sucrose. 1.5 mg of 42Ca labeled CaCl2 through IV injection<br>|
| Experimental: ACC<br>Amorphous calcium carbonate (ACC) | Other: ACC<br>* 600 mg (2 capsules of 300 mg) for oral use containing 600 mg ACC (192 mg elemental calcium) intrinsically labeled with 15 mg 44Ca 1.5 mg of 42Ca labeled CaCl2 through IV injection<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean change in fractional absorption of calcium from amorphous calcium carbonate (ACC) Vs. crystalline calcium carbonate (CCC). | Fractional absorption will be evaluated by measuring 42Ca and 44Ca levels in the urine over 24 hours (the ratio) | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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postmenopausal, women, absorption, calcium, amorphous calcium