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High-dose Vitamin D Supplements in Older Adults
NCT03613116 · View on ClinicalTrials.gov ↗
Study Summary
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.
Conditions Studied
Interventions
- DIETARY_SUPPLEMENT Vitamin D3
Study Locations (1)
California
- University of California, Davis Alzheimer's Disease Center — Walnut Creek
Trial Details
| Field | Value |
|---|---|
| Enrollment Target | 180 participants |
| Start Date | 2019-03-18 |
| Est. Completion | 2026-12-31 |
| Phase | Phase 2 |
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Full Details on ClinicalTrials.gov ↗What the Registry Record Tells You About NCT03613116
The ClinicalTrials.gov registry entry for NCT03613116 describes a study currently listed as active not recruiting. It is categorized as Phase 2, which is the standard way researchers label where a study sits along the investigational pathway from early safety work through later efficacy and post-marketing evaluation. The registered enrollment target is 180 participants, a figure that helps gauge the scale of data the investigators plan to collect. The listed sponsor is University of California, Davis, which has 653 total studies on file at ClinicalTrials.gov, and sponsors are the parties responsible for study design, oversight, and regulatory filings.
The record links to 2 conditions, with Cognitive Decline appearing as the primary indexed condition, and to 1 intervention — of which Vitamin D3 is the first listed. Interventions can include drugs, devices, procedures, behavioral programs, or observational arms, and each is tracked as a separate registry field so that downstream queries can filter accurately. When a trial lists multiple interventions, it usually reflects a multi-arm design or a comparison protocol rather than a single treatment being tested in isolation. The brief summary published in the registry is the clearest source of protocol intent and should be read before drawing conclusions from any sidebar tags.
Geographic footprint matters for practical reasons: NCT03613116 reports 1 study location spanning 1 distinct geographic area — top geographies include California. A larger site network tends to correlate with broader recruitment capacity, but it does not imply anything about study quality, and site-level enrollment status can diverge from the overall registry status shown above. Every data point on this page comes from the public ClinicalTrials.gov dataset and is reproduced here for reference only; it is not a medical recommendation, an endorsement of the sponsor, or an invitation to enroll. Verify current status, eligibility criteria, and contact details directly at ClinicalTrials.gov, and discuss any participation decision with your own healthcare provider.
Frequently Asked Questions
What is clinical trial NCT03613116 about?
NCT03613116 is a clinical study titled "High-dose Vitamin D Supplements in Older Adults". 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 vit...
What is the current status of trial NCT03613116?
This trial is currently active not recruiting. It is a Phase 2 study. The enrollment target is 180 participants. The study started on 2019-03-18. Estimated completion is 2026-12-31.
What conditions does trial NCT03613116 study?
This clinical trial studies the following conditions: Cognitive Decline, Vitamin D Deficiency. These conditions were identified from the trial registry and reflect the primary focus areas of the research.
What interventions are being tested in trial NCT03613116?
The interventions under investigation include: Vitamin D3 (DIETARY_SUPPLEMENT). Each intervention is being evaluated for safety and efficacy as part of this clinical study.
Who is sponsoring clinical trial NCT03613116?
This trial is sponsored by University of California, Davis, which has 653 total clinical trials registered on ClinicalTrials.gov. The sponsor is responsible for the study's design, funding, and regulatory compliance.
Where is trial NCT03613116 being conducted?
This trial has 1 study location across California. Contact the study sites directly through ClinicalTrials.gov for enrollment availability.
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