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
Descripción general del estudio
Estado
Condiciones
Intervención / Tratamiento
Descripción detallada
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.
Tipo de estudio
Inscripción (Actual)
Fase
- No aplica
Contactos y Ubicaciones
Ubicaciones de estudio
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New York
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Mineola, New York, Estados Unidos, 11501
- Winthrop University Hospital
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Criterios de participación
Criterio de elegibilidad
Edades elegibles para estudiar
Acepta Voluntarios Saludables
Géneros elegibles para el estudio
Descripción
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 -
Plan de estudios
¿Cómo está diseñado el estudio?
Detalles de diseño
- Propósito principal: Diagnóstico
- Asignación: Aleatorizado
- Modelo Intervencionista: Asignación de un solo grupo
- Enmascaramiento: Doble
Armas e Intervenciones
Grupo de participantes/brazo |
Intervención / Tratamiento |
|---|---|
|
Experimental: Post Menopausal
post menopausal women between the ages 50-70 yrs.
|
Dual isotope technique using stable isotopes
Otros nombres:
|
¿Qué mide el estudio?
Medidas de resultado primarias
Medida de resultado |
Periodo de tiempo |
|---|---|
|
To determine the level of 25OHD that maximizes calcium absorption efficiency.
Periodo de tiempo: 3 months
|
3 months
|
Medidas de resultado secundarias
Medida de resultado |
Periodo de tiempo |
|---|---|
|
To describe the dose response curve of calcium absorption to vitamin D intake and serum 25OHD
Periodo de tiempo: 3 months
|
3 months
|
Colaboradores e Investigadores
Patrocinador
Investigadores
- Investigador principal: John F Aloia, MD, Winthrop University Hospital
Publicaciones y enlaces útiles
Fechas de registro del estudio
Fechas importantes del estudio
Inicio del estudio
Finalización primaria (Actual)
Finalización del estudio (Actual)
Fechas de registro del estudio
Enviado por primera vez
Primero enviado que cumplió con los criterios de control de calidad
Publicado por primera vez (Estimar)
Actualizaciones de registros de estudio
Última actualización publicada (Estimar)
Última actualización enviada que cumplió con los criterios de control de calidad
Última verificación
Más información
Términos relacionados con este estudio
Palabras clave
Términos MeSH relevantes adicionales
Otros números de identificación del estudio
- 10003
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