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RecruitingAccepts healthy volunteersPhase 2

Fiber and Calcium Absorption in Older Men

VA Office of Research and Development · with San Francisco VA Health Care System · NCT06519877

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Opens the official ClinicalTrials.gov record, with the study team’s contacts. Bored Studies doesn’t enroll anyone.

Key facts

Compensation
Not posted. Ask the study team before screening.
Who can join
Ages 60+ · Men only
Healthy volunteers
Accepted
Study type
Interventional · Phase 2
Target enrollment
30
US sites recruiting
1
Study start
January 1, 2025
Record last updated
February 17, 2026

Status re-checked against ClinicalTrials.gov within the last 12 hours.

What the study is about

Osteoporotic fractures are a major but underrecognized problem in men. There is growing evidence that low dietary fiber intake is a modifiable risk factor for age-related bone loss in men. Preclinical and human studies in adolescents and postmenopausal women suggest that dietary fiber intake influences bone metabolism by modulating the gut microbiome to augment intestinal calcium absorption, but it is unclear through what molecular mechanism and whether dietary fiber has the same effects in older men. In this crossover intervention study, the investigators will enroll and follow 30 older male Veterans to evaluate the effects of soluble corn fiber on intestinal calcium absorption and explore the contribution of the gut microbiome.

Being studied: Soluble corn fiber

Conditions: Aging

Eligibility criteria

Copied from the official record. The study team makes the final decision at screening.

Show full criteria

Inclusion Criteria

  • Male Veterans 60 years of age

Exclusion Criteria

  • History of malabsorption
  • Hypercalcemia (corrected Ca > 10.2 mg/dL)
  • Vitamin D insufficiency (25OHD \< 30 ng/mL)
  • Chronic kidney disease stage 3B or worse (CrCl \< 45 mL/min)
  • Severe hypogonadism (AM fasting serum total testosterone \< 150 ng/dL)
  • Daily use of proton pump inhibitor
  • Use of medication(s) known to affect calcium metabolism
  • Use of medications or supplements that could impact gut microbiota in the previous 3 months (antibiotics or commercially available probiotics or prebiotics.
  • Presence of a condition or abnormality that in the opinion of the Investigator that would compromise the safety of the patient or the quality of the data.

Recruiting US locations

  • San Francisco VA Medical Center, San Francisco, CA

    San Francisco, CA 94121-1563

    Site contact: Karin C Wu, MD · 415-221-4810 · karin.Wu@va.gov

Study contacts (from the official record)

  • Karin C Wu, MD · (415) 221-4810 · karin.Wu@va.gov
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Fiber and Calcium Absorption in Older Men (NCT06519877) | Bored Studies