Calcium Absorption in Postmenopausal Thai Women

Overview

Adequate calcium absorption is essential for reducing one's risk of developing osteoporosis. However, postmenopausal Thai women consume diets which are habitually low in calcium due to lactose intolerance and dietary patterns which typically do not include milk-based products. The primary goal of this study is to measure the fractional calcium absorption from milk and a commonly ingested green leafy vegetable (cassia) in postmenopausal Thai women with habitually low calcium intakes. The secondary objective is to determine associations between calcium absorption and biomarkers which impact vitamin D status and bone metabolism.

Full Title of Study: “Calcium Bioavailability of Cassia Leaves in Post-Menopausal Women”

Study Type

  • Study Type: Observational
  • Study Design
    • Time Perspective: Prospective
  • Study Primary Completion Date: September 2007

Detailed Description

Postmenopausal Thai women (n=22) will be recruited from the community surrounding Bangkok and Nakhon Pathon, Thailand. They will be invited to participate in an isotope study comparing the fractional calcium absorption from milk and cassia. Upon arrival, a fasting blood sample will be drawn on the morning of the absorption study to analyze serum markers of vitamin D and bone metabolism (25-hydroxy vitamin D [25OHD], parathyroid hormone [PTH], and beta-crossLaps) and to determine their impact on calcium absorption. Following this blood draw, women will receive a stable calcium isotope (42Ca) intravenously. Then for breakfast and lunch respectively, the women will be randomly assigned to orally ingest a stable calcium isotope from either the milk (44Ca) or cassia (43Ca) test meals. On day two, women will receive a breakfast, snack, and lunch meal. Urine samples will be collected over the entire 28 hour period and the 24-hr urine collection will be used to measure urinary calcium concentration and to calculate fractional calcium absorption.

Arms, Groups and Cohorts

  • Test meal ingestion
    • On the morning of the absorption study, fasted women received 2 mg of 42Ca intravenously (in 5 ml of isotonic saline) over 5 minutes before being randomly assigned to receive either the milk or cassia meal first for breakfast and the milk or cassia meal second for lunch. The milk meal consisted of approximately 100 mg of fresh ultrahigh temperature (UHT) milk to which 2 mg of 44Ca was added and allowed to equilibrate for 12 h prior to ingestion and the cassia meal consisted of 142 g of cooked cassia to which 1 mg of 43Ca was extrinsically added.

Clinical Trial Outcome Measures

Primary Measures

  • Fractional calcium absorption
    • Time Frame: 24 hours after the ingestion of the second test meal
    • Urine samples will be collected over s 28 hour period post-dosing with collection ending 24 hours after the ingestion of the second test meal.

Secondary Measures

  • The concentration of 25-hydroxy vitamin D (25OHD) in serum
    • Time Frame: Upon entry to the study, a 10 mL blood sample will be collected in a less than 2 hour time period.
    • A fasting 10 mL blood sample will be collected upon entry into the study and used for determining the concentration of 25OHD in serum.
  • The concentration of parathyroid hormone (PTH) in serum
    • Time Frame: Upon entry to the study, a 10 mL blood sample will be collected in a less than 2 hour time period.
    • A fasting 10 mL blood sample will be collected upon entry into the study and used for determining the concentration of PTH in serum.
  • The concentration of beta-crossLaps in serum
    • Time Frame: Upon entry to the study, a 10 mL blood sample will be collected in a less than 2 hour time period.
    • A fasting 10 mL blood sample will be collected upon entry into the study and used for determining the concentration of beta-crossLaps in serum.

Participating in This Clinical Trial

Inclusion Criteria

  • Healthy – At least 3 years postmenopausal Exclusion Criteria:

  • Diagnosed gastrointestinal or metabolic diseases known to interfere with calcium absorption and metabolism – Women taking medications (including thiazide diuretics, hormonal replacement therapy, etc.) within two months prior to the study – Women taking dietary supplements within two months prior to the study

Gender Eligibility: Female

Minimum Age: 53 Years

Maximum Age: 65 Years

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • Cornell University
  • Collaborator
    • Mahidol University, Ramathibodi Hospital
  • Provider of Information About this Clinical Study
    • Sponsor
  • Overall Official(s)
    • Prapaisri P. Sirichakwal, PhD, Principal Investigator, Mahidol University

Clinical trials entries are delivered from the US National Institutes of Health and are not reviewed separately by this site. Please see the identifier information above for retrieving further details from the government database.

At TrialBulletin.com, we keep tabs on over 200,000 clinical trials in the US and abroad, using medical data supplied directly by the US National Institutes of Health. Please see the About and Contact page for details.