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High-Dose Vitamin D Supplements in Older Adults

Start: March 18, 2019
End: March 30, 2024
Enrollment: 180

What Is This Study About?

This Phase 2 study will test high-dose oral vitamin D compared to a standard dose for treating vitamin D insufficiency in a diverse group of older adults. The effects of the different doses on cognitive function will also be assessed to gather data for a potential future trial in older adults at risk for dementia. Participants will be randomly assigned to take either a high-dose tablet of vitamin D3 (4,000 IU) or a standard-dose tablet (600 IU) daily for three years. Vitamin D levels will be measured every six months through blood draws. Researchers will measure changes in cognitive function and brain structure through cognitive tests and magnetic resonance imaging (MRI) scans.

Do I Qualify To Participate in This Study?

Minimum Age: 65 Years

Maximum Age: 90 Years

Must have:

  • Low vitamin D status, as measured at screening
  • Fluent in English or Spanish
  • Willingness to be randomized to high-dose or standard dose vitamin D
  • Education-adjusted scores between 12 and 30 on the Montreal Cognitive Assessment
  • Diagnosis of no cognitive impairment, mild cognitive impairment, or mild Alzheimer's disease, as determined by cognitive and memory tests
  • Alzheimer's medications, such as donepezil and memantine, are allowed if doses have been stable for more than six weeks, and no changes are anticipated; experimental Alzheimer's therapies, such as anti-amyloid or anti-tau treatments, will be excluded

Must NOT have:

  • Lacks adequate vision, hearing, or literacy to complete psychometric tests
  • Liver insufficiency, defined by either albumin less than 3.3 g/dl or by a value more than 2 times the upper limit of normal (ULN) in either alanine aminotransaminase or bilirubin, or more than 3 times the ULN for aspartate aminotransaminase
  • Kidney insufficiency, defined by either serum creatinine greater than 1.7 mg/dl or glomerular filtration rate less than 30 ml/min/1.73 m2
  • Current serious or unstable medical illnesses including heart, liver, kidney, gastroenterologic, lung, endocrinologic, neurologic, psychiatric, immunologic, or blood disease and other conditions that could interfere with participant safety
  • Life expectancy of less than four years
  • History of recurrent kidney stones
  • Unable to undergo MRI, such as pacemaker, metallic implants, or severe claustrophobia
  • History of chronic psychiatric illness (e.g., schizophrenia or bipolar disorder), major depression within last two years, current Global Depression Scale score greater than 6, or any recent suicide attempts or suicidal ideation
  • History within the last five years of a serious infectious disease affecting the brain (including neurosyphilis, meningitis, or encephalitis), or head trauma resulting in loss of consciousness for more than 10 minutes or any persistent cognitive deficit
  • History of chronic alcohol or drug abuse/dependence within the past five years
  • History within the last five years of a primary or recurrent malignant disease with the exceptions of resected cutaneous squamous cell carcinoma in situ, basal cell carcinoma, cervical carcinoma in situ, or non-metastatic prostate cancer with a normal prostate-specific antigen post-treatment
  • Poor venous access such that multiple blood draws would be prevented
  • Prohibited medications: regular use of benzodiazepines, antipsychotics, narcotics, cholinesterase inhibitors, memantine, or anti-epileptic drugs. Stable doses of SSRI or SNRI antidepressants will be allowed if dose does not change throughout the study
  • No additional supplements containing vitamin D will be allowed

If I Qualify, Who Do I Contact?

Contact study personnel listed either under the general study contact or the location nearest you.

Study Contact
Maria Levallois
Hongzheng Zhang

Need Help?

Contact NIA’s Alzheimer’s and related Dementias Education and Referral (ADEAR) Center at 800-438-4380 or email ADEAR.

Where Is This Study Located?

University of California, Davis Alzheimer's Disease Center
Walnut Creek, CA 94598
Mitzi Hurtado

Who Sponsors This Study?

Lead: University of California, Davis

Collaborator Sponsor

  • National Institutes of Health (NIH)
  • National Institute on Aging (NIA)

Source: ID: NCT03613116