Study to Observe the Capability to Absorb Calcium as an Measure of Adequate Levels of Vitamin D



Status:Completed
Conditions:Other Indications, Postmenopausal Syndrome, Women's Studies, Gastrointestinal
Therapuetic Areas:Endocrinology, Gastroenterology, Other, Reproductive
Healthy:No
Age Range:50 - 70
Updated:2/7/2015
Start Date:December 2010
End Date:September 2011
Contact:John F Aloia, MD
Email:jaloia@winthrop.org
Phone:516-663-8793

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Calcium Absorption Efficiency As An Indicator For Vitamin D Sufficiency

The purpose of this study is to determine the capability to absorb calcium as a measure of
the sufficient levels of Vitamin D. Calcium absorption will be measured at baseline and
after vitamin D3, by dual calcium isotope technique using stable isotopes in post menopausal
women between the ages 50 and 70yrs. Subjects will have a screening visit, first and final
visits. Subjects will be randomly assigned to a placebo or daily doses of vitamin D3. The
specific aim of this study is to determine the level of vitamin D that will maximize the
absorption of calcium and establish the relationship between the administered calcium dose
and the actual absorbed calcium dose versus administered dose of Vitamin D and the serum
levels of Vitamin D.

The specific aims of this project are:

1. To determine the level of 25OHD that maximizes calcium absorption efficiency.

2. To describe the dose response curve of calcium absorption to vitamin D intake and serum
25OHD.

This will be a randomized, double-blind, placebo-controlled trial of healthy postmenopausal
females to determine the individual and combined effects of calcium and vitamin D
supplementation.70 female participants, ages 50 to 70 years of age who are menopausal for
over 1 year will be recruited into the study . The patients participation in this study will
last about 10 weeks. Approximately 70 subjects from Winthrop University Hospital and the
surrounding area will participate in this study. There is a total of 3 visits. Patients will
be fasting for all visits. The first visit is a screening visit to determine if the patients
qualify.

At visit 2, the patients will be given a light breakfast and asked to drink an 8 ounce glass
of milk or calcium fortified orange juice containing a calcium isotope. After breakfast, the
doctor or nurse will start an intravenous infusion and inject the patient with an IV
solution containing a calcium isotope. This is a stable calcium isotope that is not
radioactive and has no known toxicity. The patients will also be asked to collect a 24 hour
urine and return it to us the next day.

The volunteers will be divided into four groups:

The first group will take 800 iu daily of vitamin D supplementation. The second group will
take 2000 iu daily of vitamin D.The third group will take 4000 iu vitamin D and the fourth
group will only take placebos. Visit 3 is essentially the same as visit 2, with subjects
returning unused study medication and given new tablets

Food frequency questionnaires will be filled out at the initial visit and final visit. Diet
will be assessed using 3-day diet history form and NutritionPro analysis software. Patients
will be asked to refrain from taking other vitamin D supplements and to continue their usual
calcium intake.

Inclusion Criteria:

Post menopausal women between the ages 50-70 yrs.

Exclusion Criteria:

1. Any chronic medical illness including diabetes mellitus, history of myocardial
infarction, or heart failure, malignancy, uncontrolled hypertension, history of
anemia, leukemia, or other hematologic abnormalities, lupus, rheumatoid arthritis, or
other rheumatologic disease, or kidney disease of any kind as determined by history
and physical examination.

2. Subjects with a BMI >35kg/m2

3. Use of medication that influences vitamin D and bone metabolism (i.e. anticonvulsant
medications, glucocorticoids, HAART [AIDS treatment], antirejection medications, high
dose diuretics etc).

4. Significant deviation from normal either in history, physical examination, or
laboratory tests as evaluated by the primary investigator.

5. Patients with a history of hypercalciuria ( Urine calcium:creatinine ratio > 0.37 ,
hypercalcemia ( serum calcium >10.21, nephrolithiasis, and active sarcoidosis will
also be excluded.

6. Unexplained weight loss >15% during the previous year or history of anorexia nervosa

7. Participation in another investigational trial in the past 30 days prior to the
screening evaluation.

8. Patients reporting alcohol intake greater than 2 drinks daily.

9. Subjects with baseline 25-OHD level greater than 70 nmol /L will be excluded.

10. Smokers greater than one pack per day will be excluded

11. Dietary calcium intake greater than 2000 mg will be excluded

12. Participants who have history of allergy to milk, gluten or orange juice will be
excluded

13. Participants willing not to forego multivitamins and vitamin D supplements during the
study -
We found this trial at
1
site
259 1st St
Mineola, New York 11501
(516) 663-0333
Winthrop University Hospital Founded in 1896 by a group of local physicians and concerned citizens,...
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Mineola, NY
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