High-dose Vitamin D Supplements in Older Adults
Public ClinicalTrials.gov record NCT03613116. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
Phase II RCT of High-dose Vitamin D Supplements in Older Adults
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
This Phase II randomized clinical trial aims to test if supplementation with high dose oral vitamin D will successfully correct vitamin D insufficiency, compared to treatment with standard (RDA) dose vitamin D in a diverse community-based elderly cohort. The effect of high-dose vs. standard-dose vitamin D on altering cognitive trajectories will also be assessed and data will be expected to be used in designing a potential definitive Phase III trial in elderly groups at risk for dementia. A total of 180 elderly persons with longitudinal biomarkers, neuropsychological testing and brain MRI scans will be enrolled, with 152 (\~50 with MCI, 50 with mild AD and 50 with no cognitive impairment) expected to complete the 3½-year study. One-half of each diagnostic group will be randomized to treatment with high-dose vitamin D3 (4,000 IU daily) or to standard dose Vitamin D (600 IU capsule daily + \~200 IU dietary = \~800 IU total/day). Longitudinal MRI analyses will provide an estimate of the treatment effect size on brain atrophy rate. Vitamin D receptor genotype polymorphisms and their impact on response to oral supplementation will also be examined. If vitamin D supplementation improves cognitive outcome, this could have a large impact on the public health, since low vitamin D status is a common, readably treatable condition which may provide a novel window to prevent dementia and AD. Furthermore, the higher prevalence of AD and dementia in African Americans and Latinos could be partially attributable to vitamin D insufficiency.
Study identification
- NCT ID
- NCT03613116
- Recruitment status
- Active, not recruiting
- Study type
- Interventional
- Phase
- Phase 2
- Enrollment
- 180 participants
Conditions and interventions
Conditions
Eligibility (public fields only)
- Age range
- 65 Years to 90 Years
- Sex
- All
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Mar 17, 2019
- Primary completion
- Dec 30, 2026
- Completion
- Dec 30, 2026
- Last update posted
- Apr 2, 2026
2019 – 2026
United States locations
- U.S. sites
- 1
- U.S. states
- 1
- U.S. cities
- 1
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| University of California, Davis Alzheimer's Disease Center | Walnut Creek | California | 94598 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT03613116, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Apr 2, 2026 · Synced Sep 1, 2026
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Open the official record
The complete protocol, eligibility criteria, and contact information for NCT03613116 live on ClinicalTrials.gov.