Study to Observe the Capability to Absorb Calcium as an Measure of Adequate Levels of Vitamin D
Calcium Absorption Efficiency As An Indicator For Vitamin D Sufficiency
Studieöversikt
Status
Betingelser
Intervention / Behandling
Detaljerad beskrivning
The specific aims of this project are:
- To determine the level of 25OHD that maximizes calcium absorption efficiency.
- 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.
Studietyp
Inskrivning (Faktisk)
Fas
- Inte tillämpbar
Kontakter och platser
Studieorter
-
-
New York
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Mineola, New York, Förenta staterna, 11501
- Winthrop University Hospital
-
-
Deltagandekriterier
Urvalskriterier
Åldrar som är berättigade till studier
Tar emot friska volontärer
Kön som är behöriga för studier
Beskrivning
Inclusion Criteria:
Post menopausal women between the ages 50-70 yrs.
Exclusion Criteria:
- 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.
- Subjects with a BMI >35kg/m2
- Use of medication that influences vitamin D and bone metabolism (i.e. anticonvulsant medications, glucocorticoids, HAART [AIDS treatment], antirejection medications, high dose diuretics etc).
- Significant deviation from normal either in history, physical examination, or laboratory tests as evaluated by the primary investigator.
- 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.
- Unexplained weight loss >15% during the previous year or history of anorexia nervosa
- Participation in another investigational trial in the past 30 days prior to the screening evaluation.
- Patients reporting alcohol intake greater than 2 drinks daily.
- Subjects with baseline 25-OHD level greater than 70 nmol /L will be excluded.
- Smokers greater than one pack per day will be excluded
- Dietary calcium intake greater than 2000 mg will be excluded
- Participants who have history of allergy to milk, gluten or orange juice will be excluded
- Participants willing not to forego multivitamins and vitamin D supplements during the study -
Studieplan
Hur är studien utformad?
Designdetaljer
- Primärt syfte: Diagnostisk
- Tilldelning: Randomiserad
- Interventionsmodell: Enskild gruppuppgift
- Maskning: Dubbel
Vapen och interventioner
Deltagargrupp / Arm |
Intervention / Behandling |
|---|---|
|
Experimentell: Post Menopausal
post menopausal women between the ages 50-70 yrs.
|
Dual isotope technique using stable isotopes
Andra namn:
|
Vad mäter studien?
Primära resultatmått
Resultatmått |
Tidsram |
|---|---|
|
To determine the level of 25OHD that maximizes calcium absorption efficiency.
Tidsram: 3 months
|
3 months
|
Sekundära resultatmått
Resultatmått |
Tidsram |
|---|---|
|
To describe the dose response curve of calcium absorption to vitamin D intake and serum 25OHD
Tidsram: 3 months
|
3 months
|
Samarbetspartners och utredare
Sponsor
Utredare
- Huvudutredare: John F Aloia, MD, Winthrop University Hospital
Publikationer och användbara länkar
Studieavstämningsdatum
Studera stora datum
Studiestart
Primärt slutförande (Faktisk)
Avslutad studie (Faktisk)
Studieregistreringsdatum
Först inskickad
Först inskickad som uppfyllde QC-kriterierna
Första postat (Uppskatta)
Uppdateringar av studier
Senaste uppdatering publicerad (Uppskatta)
Senaste inskickade uppdateringen som uppfyllde QC-kriterierna
Senast verifierad
Mer information
Termer relaterade till denna studie
Nyckelord
Ytterligare relevanta MeSH-villkor
Andra studie-ID-nummer
- 10003
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