A Study on the Impact of Calcium on Woman's Vascular Health

Study Overview
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Brief Summary
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The overarching aim of this randomized clinical trial is to estimate the effect of dietary intake of calcium as compared to supplemental calcium on the vascular system and markers of vascular and bone health in postmenopausal women.

Detailed Description
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Calcium and vitamin D are essential nutrients for optimal bone health throughout life. Research has shown that postmenopausal women who consume appropriate amounts of these nutrients have better bone strength and fewer fractures than those who don't. However, researchers have recently questioned the safety of calcium and vitamin D obtained through supplements as they might increase the risk of cardiovascular events such as heart attacks and strokes. The investigators propose to estimate the effect of dietary intake of calcium as compared to supplemental calcium on vascular and bone health in postmenopausal women. Eligible participants will be assigned by chance (like a coin toss) to one of three groups: (1) 1200 mg of calcium from dietary sources and 1 capsule of 400 IU vitamin D supplement everyday after the first meal of the day; (2) 450 mg of calcium from dietary sources, 2 tablets of 250 mg calcium citrate supplement and 1 capsule of 800 IU vitamin D supplement everyday after the first meal of the day and 1 tablet of 250 mg calcium citrate supplement after the evening meal or snack; or (3) unrestricted calcium from dietary sources and 1 capsule of 400 IU vitamin D supplement everyday after the first meal of the day. Participants have an equal chance of being assigned to any of these three groups until 26 participants have been assigned to group (3). At this time participants will continue to be assigned by chance to either of the two remaining groups only. Participants will also attend appointments at the Montreal General Hospital every 6-months where they will undergo anthropometric measurements, blood tests, urine tests, non-invasive ultrasounds to measure arterial stiffness and questionnaires. The questionnaires ask about health; lifestyle habits such as physical exercise, diet, and smoking; use of medications and dietary supplements; family history of illness, and past medical diagnoses. Participants will also receive monthly phone calls from study staff to monitor for adverse events and adherence.

Official Title
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The Effect of Dietary Calcium Intake as Compared to Calcium Supplementation on Vascular Health and Bone Health in Postmenopausal Women

Conditions
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Osteoporosis, Cardiovascular Diseases

Intervention / Treatment
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* Dietary Supplement: Calcium Citrate
* Other: Low Dietary Calcium
* Other: High Dietary Calcium


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Women aged 50 or more 2 years since last menstrual period Body Mass Index between 20 and 35 kg/m2 Exclusion Criteria: Atrial Fibrillation Coronary artery disease Myocardial infarction Stroke Transient ischaemic attack Peripheral vascular disease Sleep apnea Hypertension Hyperlipidemia Hyperparathyroidism Urinary tract lithiasis Rheumatoid arthritis Crohn's disease Ulcerative colitis Short gut syndrome Celiac disease Diabetes Cancer (any other than basal cell cancer of the skin) Pre-eclampsia Smoked in the last 5 years Cocaine use in the last year Consumption of more than 9 alcoholic drinks per week Chronic NSAID use Use of oral glucocorticoids or HRT (excluding vaginal preparations) in the last 2 years Use of anti-osteoporosis medications (bisphosphonates, selective estrogen-receptor modulators, denosumab, teriparatide, or calcitonin) in the last 3 years or anti-osteoporosis therapy which ended more than 3 years ago and whose duration was ≥ 5 years, or a fracture of the spine, shoulder, or hip was sustained while therapy Use of calcium and vitamin D supplements (including multivitamins and calcium-containing antacids) in the last 2 months High 10-year probability of major osteoporotic fracture (FRAX without BMD > 20%)

Ages Eligible for Study
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Minimum Age: 50 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: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Supplemental Calcium<br>750 mg Calcium Citrate per day 800 IU Vitamin D3 per day Low Dietary Calcium (450 mg per day) | Dietary Supplement: Calcium Citrate<br>* 750mg<br>Other: Low Dietary Calcium<br>* 450 mg<br>|
| Active Comparator: Dietary Calcium<br>400 IU Vitamin D3 per day High Dietary Calcium (1200 mg per day) | Other: High Dietary Calcium<br>* 1200 mg<br>|
| No Intervention: Usual Diet<br>400 IU Vitamin D3 per day Unrestricted Dietary Calcium | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Vascular System | Measured as changes in: Arterial stiffness (carotid-femoral pulse wave velocity) Arterial wall thickness (carotid intima-media thickness) | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hemodynamics | Measured as changes in: - Peripheral blood pressure | 12 Months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Calcium Supplements, Dairy Foods, Cardiovascular Diseases, Osteoporosis, Postmenopause, Vitamin D, Micronutrients, Primary Prevention, Bone Health