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Sponsors and Collaborators: |
National Institute on Aging (NIA) Rutgers University |
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Information provided by: | National Institute on Aging (NIA) |
ClinicalTrials.gov Identifier: | NCT00472654 |
The purpose of this study is to learn how the amount of vitamin D supplementation influences intestinal fractional calcium absorption (a measure of the amount of calcium absorbed).
Condition | Intervention |
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Weight Loss Bone Density |
Behavioral: Weight Loss Dietary Supplement: Vitamin D 1200 IU Behavioral: Weight Maintenance |
Study Type: | Interventional |
Study Design: | Treatment, Randomized, Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Placebo Control, Parallel Assignment, Efficacy Study |
Official Title: | Nutritional Regulation of Bone - Aim 3 |
Estimated Enrollment: | 84 |
Study Start Date: | March 2007 |
Estimated Study Completion Date: | May 2011 |
Estimated Primary Completion Date: | May 2011 (Final data collection date for primary outcome measure) |
Arms | Assigned Interventions |
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WL: Placebo Comparator |
Behavioral: Weight Loss
Diet for weight loss for 5 weeks; all weight loss participants will attend 5-6 weekly counseling sessions (about 50 minutes per session)
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WL + D: Experimental |
Behavioral: Weight Loss
Diet for weight loss for 5 weeks; all weight loss participants will attend 5-6 weekly counseling sessions (about 50 minutes per session)
Dietary Supplement: Vitamin D 1200 IU
Daily Vitamin D 1200 IU supplement for 5 weeks
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WM: Placebo Comparator |
Behavioral: Weight Maintenance
Diet for weight maintenance for 5 weeks
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WM + D: Active Comparator |
Dietary Supplement: Vitamin D 1200 IU
Daily Vitamin D 1200 IU supplement for 5 weeks
Behavioral: Weight Maintenance
Diet for weight maintenance for 5 weeks
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The extent of change in the amount of calcium that is absorbed with an increase in vitamin D supplementation is not known. This information is important for determining appropriate vitamin D requirements for optimal calcium absorption. During caloric restriction in postmenopausal women, we found that serum parathyroid hormone (PTH) explains 22% of the variance for the reduced calcium absorption (equivalent to 400 IU of Vitamin D per day). It is possible that higher dietary Vitamin D will increase serum 25-hydroxy-Vitamin D (25(OH)D) levels, offset serum PTH and thereby prevent a reduction in calcium absorption. This study seeks to determine if a high Vitamin D intake (a supplement of 1200 IU per day) can increase true fractional calcium absorption (TFCA) in postmenopausal women on a standard high-carbohydrate weight loss diet compared to weight maintenance, with the hypothesis that a high Vitamin D intake will raise serum 25(OH)D and offset the decline in TFCA during caloric restriction (vs. an increase in weight-stable women), and serum PTH will no longer be a major factor explaining changes in TFCA.
Participants will be recruited for both weight loss and weight maintenance, and all will be randomly assigned to take either 1200 IU per day vitamin D supplement or matching placebo. All weight loss participants will attend 5-6 weekly counseling sessions (about 50 minutes per session). All participants will be asked to take a daily vitamin/mineral supplement and, depending on their usual food intake, they may be asked to take a calcium tablet to meet the recommended intake throughout the study period. To measure calcium absorption before and after the 6 weeks of weight loss, participants will go to the study site after an overnight fast where an IV will be placed and the participant will receive an infusion of a stable calcium isotope and consume a 4 oz beverage that also contains a stable isotope of calcium. Blood will be drawn, and then the participant will be asked to collect all urine for the next 24 hours. Body composition (fat, muscle mass, and bone mineral density) will be measured by a dual-energy x-ray absorptiometry (DXA) machine and peripheral quantitative computer tomography (pQCT).
Participants will only be recruited in the winter and spring of each year.
Ages Eligible for Study: | 50 Years to 70 Years |
Genders Eligible for Study: | Female |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
Exclusion Criteria:
United States, New Jersey | |
Rutgers University | Recruiting |
New Brunswick, New Jersey, United States, 08901 | |
Contact: Sue Shapses, PhD, RD 732-932-9403 shapses@aesop.rutgers.edu | |
Contact: Hasina Ambia-Sobhan 732-932-6656 togore@rci.rutgers.edu | |
Principal Investigator: Sue Shapses, PhD, RD | |
Sub-Investigator: Stephen Schneider, MD | |
Sub-Investigator: Robert Brolin, MD |
Principal Investigator: | Sue Shapses, PhD, RD | Rutgers University, Nutritional Sciences |
Responsible Party: | Rutgers University ( Sue Shapses, PhD, RD ) |
Study ID Numbers: | AG0083, RO1-AG12161 |
Study First Received: | May 10, 2007 |
Last Updated: | September 11, 2008 |
ClinicalTrials.gov Identifier: | NCT00472654 |
Health Authority: | United States: Federal Government |
bone mass calcium absorption bone quality fracture risk |
Body Weight Calcium, Dietary Signs and Symptoms Vitamin D |
Weight Loss Fractures, Bone Ergocalciferols Body Weight Changes |
Growth Substances Vitamins Physiological Effects of Drugs |
Bone Density Conservation Agents Micronutrients Pharmacologic Actions |