Active — Not RecruitingPhase 2

High-dose Vitamin D Supplements in Older Adults

United States180 participantsStarted 2019-03-18

Plain-language 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.

Who can participate

Age range

65 Years – 90 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Inclusion criteria for this study are: 1) Age 65-90; 2) Low Vitamin D status, defined by a serum 25-OHD \<20 ng/ml, as measured by competitive immunoassay at the Screening visit; 3) Fluent in either English or Spanish; 4) Willingness to be randomized to high-dose vs. standard dose vitamin D; 5) Education adjusted scores between 12-30 on the Montreal Cognitive Assessment (MOCA) at baseline; 6) A consensus clinical diagnosis of No Cognitive Impairment, Mild Cognitive Impairment, or mild AD dementia. * In order to be included in the No Cognitive Impairment (NC) subgroup, an individual must show no significant cognitive impairment on the baseline neuropsychological tests. Diagnoses are made by a comprehensive case conference review, including investigators from both sites, resulting in a consensus diagnosis made according to current research criteria. We will also require a minimum MOCA score of 23 or above for those with education \>12 y, or MOCA \>20 (uncorrected score) for those with education \<12 years. These subjects are expected to mostly have CDR global scores of 0, but we will not exclude CDR=0.5, as long as Peterson criteria (Petersen, Journal of Internal Medicine 2004) for MCI (amnestic or non-amnestic) are not met and the CDR-Sum of Boxes is \<1.0. Similarly, we will not exclude elderly with subjective memory complaints from the NC group. * In order to be included in the Mild Cognitive Impairment (MCI) subgroup, a participant will need to meet r…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Correction of VitD insufficiency

Timeframe: Expect vitamin D levels to correct by 1-2 month on treatment

SENAS Executive Function Composite Score

Timeframe: 3.5 years

Trial details

NCT IDNCT03613116

SponsorUniversity of California, Davis

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2026-12-31

View on ClinicalTrials.gov More Vitamin D Deficiency trials