High-dose Vitamin D Supplements in Older Adults
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 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.
1. General Design This Phase 2 randomized clinical trial of high-dose vs. standard dose
 Vitamin D (VitD) supplementation aims to prove feasibility of the intervention in a
 diverse community-recruited cohort and to provide an estimate of the effect sizes of
 treatment on cognitive change and brain MRI volumetric measures as the main outcomes. We
 will study 180 elderly participants (approximately 60 with MCI, 60 with mild AD and 60
 with No Cognitive Impairment) with longitudinal neuropsychological testing and brain MRI
 scans over a 3½ year study period. One-half of each diagnostic group will be randomized
 to treatment with high-dose (4,000 IU p.o. daily) vitamin D3 (n=90) or to standard dose
 vitamin D3 treatment (n=90 who will receive 600 IU vitamin D3 daily). The choice of the
 low-dose amount of vitamin D3 was determined by the goal to meet the Institute of
 Medicine (IOM) RDA recommendation of 800 IU/day for older adults (age >71y) from all
 sources, including both diet and supplements. The estimated average dietary intake of
 VitD by older adults is ~200 IU/day. Thus, the combined intake of VitD from diet and the
 low-dose supplement in our study will be approximately the RDA (i.e. 800 IU/day). Blood
 will be collected every 6 months (except month 30) for VitD levels along with other
 clinical labs.

 This study aims to test if supplementation with high dose oral VitD (4,000 IU) will
 successfully correct VitD insufficiency, compared to treatment with standard RDA dose
 VitD (~800 IU total intake, as recommended by the IOM for those >age 71) in a diverse
 community-based cohort with serum VitD levels <20 ng/ml at study entry. The primary aims
 are to prove feasibility of the intervention, and the effectiveness of high-dose VitD in
 correcting VitD insufficiency in this diverse old cohort. Our primary outcome will be
 correction of VitD insufficiency in all subjects treated with 4,000 IU daily. Secondary
 aims are to provide an estimate of the effect sizes of treatment on cognitive change
 (executive function and global), and to gather preliminary data relevant to the evidence
 for moving forward with a potential definitive Phase III study in elderly groups at risk
 for dementia. Additional analyses will test if correction of VitD insufficiency
 correlates with changes in key biomarkers measured in blood and urine. Longitudinal MRI
 analyses will provide an estimate of the treatment effect size on brain atrophy rate. We
 will also examine VitD receptor genotype polymorphisms and their impact on response to
 oral supplementation.

 2. Schedule of Visits Screening Visit (Visit 1). Elderly participants with a prior
 diagnosis of either No Cognitive Impairment, MCI, or mild AD, will be screened for
 potential study entry. Informed consent will be obtained before any study procedures are
 conducted. The following assessments will be done at screen (before Visit 2): MOCA, GDS,
 CDR, screening labs, then brain MRI for those who remain eligible. Blood and urine
 screening lab results will be reviewed by the investigator or designee for assessment of
 eligibility. Patients who do not meet all inclusion criteria or who meet any exclusion
 criteria will be discontinued from the study. Up to 45 days are allowed for completion
 of Visit 1 screening procedures, assessments, and evaluation of results from laboratory
 tests and Brain MRI.

 Baseline Visit (Visit 2). The treatment period is a double-blind phase beginning at
 Visit 2, with treatment duration of 3½ years from baseline to the final 42 month visit.
 Patients who meet entry criteria will be enrolled and randomized to high-dose VitD 4,000
 IU p.o. daily or standard dose VitD (600 IU daily). Randomization will be stratified by
 diagnosis and race, such that 50% of each diagnostic subgroup will be randomized to the
 high-dose treatment arm.

 Assessments to be performed at the Baseline visits are: additional neuropsychological
 tests including the SENAS and ADAS-Cog, the ECog which has sections completed by the
 participant and the informant. Blood samples drawn at the Screening or Baseline visit
 will be sent for measurements of parathyroid hormone (PTH) level and genotyping to
 include polymorphisms of the VitD receptor for all enrolled subjects.

 Telephone Check-Ins at Months 1 and 30. Brief telephone calls will be made to all
 enrolled participants at Month 1 & Month 30 to check on compliance with the study
 medication.

 Treatment Period Visits at Months 6 and 18 (Visits 3 & 5). Brief visits will be
 performed at Month 6 and Month 18, with venipuncture for blood VitD level and the
 ADAS-Cog. In addition, pill counts and study drug compliance will be reviewed and
 documented.

 Treatment Period Visits at Months 12, 24, 36 and 42 (Visits 4, 6, 8 & 9). These visits
 will provide the main outcome measures for the trial. Assessments to be performed at
 these visits are: Neuropsychological testing with the SENAS, MOCA and the ADAS-Cog.
 Functional assessment instruments (collected from the participant and informant) are the
 ECog and CDR. The GDS will also be collected. Blood samples will be drawn for
 measurement of VitD level, and both plasma and serum will be stored for additional
 studies. The final assessment visit at Month 42 (Visit 9) will take place on the day of
 the patient's last VitD dose. A volumetric brain MRI study will also be obtained at this
 visit.

 Early Termination (ET) Visit (if applicable). For participants who do not complete this
 42 month study, an early termination visit will be done whenever possible. For the early
 termination visits, we plan to obtain all the measures usually collected at Month 42.

 3. Protocol Procedures. Medical History, Physical, and Neurological Exam: A complete
 medical history with review of systems, and recent medication history will be performed
 at screening. All study patients will receive a comprehensive physical examination at
 screening and annually. A detailed neurological exam will be performed either at
 screening or baseline. Any deficits identified will be documented using a standardized
 form. The physician also takes a functional history, and a psychiatric/behavioral
 history. Participants will be closely monitored during the treatment period (from month
 1 through 42) to assess side effects or adverse events.

 Blood draws and Laboratory Tests. Blood samples will be collected into serum separator
 tubes (to collect serum) containing EDTA. One EDTA tube will be sent directly to the UC
 Davis Medical Center (UCDMC) clinical lab for a complete blood count and measurement of
 hemoglobin A1C. A second EDTA tube will be centrifuged at 40C to collect plasma. The
 buffy coat of the second tube will be collected and frozen for subsequent isolation of
 genomic DNA. Serum and plasma samples will be aliquoted in volumes specific for each
 assay, and frozen at -800C until analysis.

 Laboratory Assays VitD (25-OHD) level will be performed at screen and every 6 months
 after (serum/blood, except for the month 30 Telephone check-in visit). Clinical Labs
 (screening): Comprehensive Metabolic Panel (CMP), CBC, UA, vitamin B12 at screen. PT/PTT
 will be drawn for any participant with history of a coagulopathy or excessive bleeding.
 If none of the above screening labs are exclusionary, we will add homocysteine, PTH,
 high-sensitivity CRP, Interleukin-6 (IL-6), IL-10, TNF-alpha, Monocyte chemoattractant
 protein-1 (MCP-1), blood and urine Isoprostane F 2-α levels. Inflammatory markers:
 annual CRP blood levels and cytokine panel (IL-6, IL-10, TNF-alpha, and MCP-1) will be
 measured at Baseline and month 42 (or ET visit). Oxidative damage markers: Isoprostane F
 2-α levels in blood and urine will be measured at Baseline and month 42 (or ET visit).
 Genetic analysis of the VitD receptor will be carried out for SNPs previously associated
 with cognitive decline or AD: Apa1, Taq1, CdX, and Bsml. For safety purposes, the
 following Labs will be done as needed: Urine & serum Calcium PRN renal stones, cultures
 (e.g. urine, blood) and Microbiology tests if with high wbc count. We will repeat CMP
 annually (months 12, 24, 36 & 42), and PTH level at month 42 (or ET visit).

 Neuropsychological Testing. All subjects will undergo neuropsychological testing with
 the MOCA at screening and at the 12, 24, 36 and 42 month visits. The Spanish English
 Neuropsychological Assessment Scale (SENAS) will be administered at baseline and at the
 12, 24, 36 and 42 month office visits. The ADAS-Cog will be administered at baseline and
 every 6 months (except month 30).

 Functional Assessments. All subjects will undergo functional assessments with the ECog
 (informant based measure of daily function) and CDR at screen/baseline and at months 12,
 24, 36, and 42.

 Dietary Survey. Dietary data will be collected to assess overall intake of VitD from
 food sources. Participants or their caregivers will be interviewed using a validated
 VitD Questionnaire.

 Other Clinical Instruments/Assessments. All subjects will complete the Geriatric
 Depression Scale (GDS) at screening and at the 12, 24 & 42 month assessments.

 Brain MRI Procedure & Analysis. Structural Brain MRI will be acquired at Screening and
 at study end (42 months, or at time of ET visit) for all enrolled participants. Subjects
 will be scanned at the UC Davis Imaging Research Center using a 3 Tesla Siemens Tim Trio
 machine and ADNI-compatible pulse sequences.

 MRI acquisition and analysis. MRI acquisition will include T1-weighted, fast T2,
 fluid-attenuated inversion recovery (FLAIR), and diffusion tensor imaging (DTI). MRI
 data will be analyzed for quantification of regional brain, gray, white and CSF volumes.
 All subjects will have baseline and longitudinal quantification of regional WMH, DTI and
 gray matter measures.

 4. Statistical Analysis Plan (SAP), Hypothesis Testing & Statistical Considerations.

 A brief description of hypothesis testing strategies and power calculations are provided
 separately by aim below. All power calculations assumed a two-sided test and alpha=0.05
 unless otherwise specified.

 Aim 1: To compare the effectiveness of high-dose versus standard-dose oral VitD in
 correcting low VitD status in a diverse community-based cohort.

 Hypothesis 1.1: Rate of correction of VitD insufficiency is higher after high-dose
 versus standard dose oral VitD supplementation.

 Analytic Plan. The primary analyses for this aim will involve two parts: 1) a
 descriptive summary of the percentage of individuals randomized to each group whose VitD
 levels reach and continue in the adequate range (>20 ng/ml); and 2) a comparison of the
 percentage of individuals whose levels reach the adequate range between the high-dose
 and standard dose groups. We will compute the percentage of individuals who attain
 adequate VitD levels by six months, the percentage who maintain these levels from months
 6 through 42, and 95% confidence intervals. A stratified exact test of proportions will
 be used to compare percentages between groups. Secondary analyses will characterize the
 trajectory of VitD levels in the two groups over time using mixed effects models to
 assess patterns of change, and in particular, whether levels plateau or continue to
 increase.

 Power calculations. With 76-90 individuals per group, we will have over 80% power to
 detect a difference in percentage that reach or maintain adequate levels between groups
 assuming the percentage in the high-dose group is at least 90% and the percentage in the
 standard-dose group is no more than 72%.

 Aim 2: To assess the effect of high-dose vs. standard-dose VitD on altering cognitive
 trajectories, and gather preliminary data relevant to the design of a potential Phase
 III trial in elderly at-risk groups.

 Hypothesis 2.1: High dose VitD supplementation is associated with less cognitive decline
 (better cognitive trajectory) in executive function over 3 ½ years than in those
 receiving the standard dose.

 Rationale. Published data from our observational study showed a significant difference
 in rates of decline between those with insufficient or deficient serum VitD levels and
 those whose levels are in the adequate range. If high-dose VitD supplementation results
 in a slowing of cognitive decline, similar to that seen between the decline in the
 inadequate or deficient group and the adequate group, in addition to evidence of
 effectiveness (Aim 1) and biological mechanism (Aim 3), such a result would support
 moving on to a Phase III clinical trial for a definitive demonstration of clinical
 efficacy of high-dose VitD.

 Analytic Plan. The primary outcome for this aim is the SENAS executive function score,
 assessed annually over the course of the trial. A secondary outcome is the ADAS-Cog
 (global cognition). The analytic strategy is the same for each outcome and will utilize
 an intent-to-treat approach in which everyone randomized to the high dose group will be
 compared to those randomized to the standard dose regardless of adherence to treatment;
 secondary as-treated analyses will utilize continuous serum VitD levels as a measure of
 exposure to VitD to assess a "dose-response" relationship. Mixed effects regression
 models, similar to those described above for the secondary analyses for VitD
 trajectories will be used to assess differences in rates of decline. Models will further
 include age, education, ethnicity, ApoE4 status, BMI, and season of blood draw as
 covariates. Secondary analyses will compare those with adequate serum VitD levels by six
 months (who sustain levels throughout the treatment period) to those with continued VitD
 insufficiency. Further secondary analyses will utilize the continuous serum VitD levels
 as time-varying variables in the models to assess how levels over time are associated
 with level and change in cognitive function.

 Power calculations. Because this Phase II trial will assess preliminary evidence of
 efficacy, the type I error rate (alpha) will be set at 0.05 and power will be based on a
 one-tailed test as is standard for Phase II trials to assess whether rates of decline
 are slower in the high-dose group than in the standard-dose group. Using estimates of
 between and within-person variability in change in executive function from preliminary
 data, with 76 individuals (completers) per group, we will have 80% power to detect a
 difference in the rate of executive function decline, based on the effects seen in our
 observational study. We allow for up to a 15.5% drop out rate with dropout uncorrelated
 to missing data.

 Aim 3 (exploratory): To compare the effects of high-dose VitD versus standard-dose VitD
 on key brain, blood and urine biomarkers relevant to healthy brain aging.

 Hypothesis 3.1: High dose VitD supplementation is associated with less brain atrophy
 (total gray + white matter volume) and less loss of hippocampal volume over 3 ½ years
 than in those on standard dose VitD.

 Hypothesis 3.2: Blood inflammatory markers are lower in persons on high-dose VitD
 supplementation compared to persons on standard dose VitD.

 Hypothesis 3.3: Blood and urine markers of oxidative stress are lower in persons on
 high-dose VitD supplementation compared to persons on standard dose VitD.

 Rationale. MRI, blood and urine markers provide information on the potential biological
 mechanisms of VitD supplementation, and in particular, correction of VitD insufficiency.
 These exploratory hypotheses will provide further evidence of the benefit of VitD
 supplementation in at risk elderly individuals.

 Analytic Plan The analysis strategy will be similar for each of these hypotheses. MRI
 and measures from blood (e.g. CRP, IL-6, IL-10, TNF-alpha), and urine (e.g. isoprostane)
 will be acquired at baseline and at month 42 (or the ET). The primary outcome will be
 the value from the final visit. Because this is a randomized trial, it is expected that
 the baseline means will be similar in the two groups, so that a primary comparison of
 the measure at the final visit provides an assessment of the impact of high- vs standard
 dose VitD supplementation. Linear regression, using the baseline measure as a covariate
 will be used. Other covariates, including age, and ApoE4 status will be included in the
 models. To account for differences in the timing of the final visit (since some may be
 terminal visits prior to the end of the trial), time since baseline will be included.
 Model assumptions of normality of the residuals, constant variance, and linearity will
 be checked and transformations or nonlinear models will be used if needed. Secondary
 analyses will compare those individuals who have sustained corrected VitD levels versus
 those who remain insufficient. Hypotheses will be supported if the average levels at the
 terminal visit are improved in the high-dose group relative to the standard dose group.

 Power calculations. With 152 individuals, we will have 80% power to detect a difference
 between groups as small as 0.46 standard deviations (SD). Using data from the
 Alzheimer's Disease Neuroimaging Initiative, brain atrophy and hippocampal atrophy over
 3 ½ years between Normal and MCI individuals ranged from 0.53-0.69 SD. Therefore, we
 will have sufficient power to detect a slowing in atrophy rates comparable to an
 improvement of the MCI subjects to the rate of cognitively normal individuals through
 VitD supplementation.

 Additional exploratory analyses. Additional analyses will examine the effects of
 high-dose VitD on measures of mood (GDS), using the GDS as the outcome in mixed effects
 regression models. Because response to VitD supplementation may differ by VitD receptor
 genotype, the association between genotype and cognitive decline and brain atrophy will
 be explored by adding genotype to the models used for Aim 2 and Hypothesis 3.1. For
 planning of the Phase III clinical trial, differences in effects by diagnosis will be
 explored. We will biobank serum and plasma making these materials available for further
 analyses which could include metabolomics and further genetic characterization.

 5. Safety analyses. The Data Safety Monitoring Board for this study will review Adverse
 Events and all safety data collected every six months, commencing with the first patient
 enrolled. The DSMB will be particularly concerned with falls and fractures, renal
 stones, hepatic/renal insufficiency, and achieving extremely high levels of VitD.
 Frequencies of these events will be recorded and compared between the high- and standard
 dose groups. Overall, we expect the tolerability of VitD supplementation to be excellent
 in this population, but will test if safety and aspects of health are superior/inferior
 in either of the treatment arms.
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 research criteria for amnestic MCI, either single-domain or
 multiple-domain (McKhann et al, Neurology 1984). Thus, participants with amnestic MCI
 will have standardized memory scores >1.5 SDs below average, and if cognitive scores
 in other cognitive domains are also >1.5 SDs below average they will be classified as
 multiple-domain amnestic MCI. All MCI participants will be required to have a global
 CDR=0.5. In addition, we will require a minimum MOCA score of >20 for those with
 education >12 y, or MOCA >17 (uncorrected score) for those with education <12 years.

 -  In order to be included in the Mild AD dementia subgroup, a participant will need to
 meet research criteria for probable or possible AD (McKhann et al, Neurology 1984). A
 global CDR score of 1 will be required (mild dementia). In addition, we will require a
 minimum MOCA score of >15 at entry for those with education >12 y, or MOCA >12
 (uncorrected score) for those with education <12 y. AD therapies will be allowed (e.g.
 donepezil, memantine) as long as doses have been stable for >6 weeks, and no changes
 in doses or CNS active medications are planned while participating in this trial.

 Exclusion Criteria:

 -  Exclusion criteria (for all participants) are: 1) Lacks adequate vision, hearing, or
 literacy to complete the required psychometric tests (e.g. severe bilateral deafness
 despite use of hearing aids, or visual acuity poorer than 20/100 in both eyes); 2)
 Hepatic insufficiency, defined by either albumin <3.3 g/dL or by a value >2X the upper
 limit of normal (ULN) in either alanine aminotransaminase (ALT/SGPT) or bilirubin, or
 >3X the ULN for aspartate aminotransaminase (AST/SGOT); 3) Renal insufficiency,
 defined by either serum creatinine >1.7 mg/dL or glomerular filtration rate <40
 mL/min/1.73 m2; (calculated per CKD-EPI formula). 4) Hypercalcemia, defined by serum
 calcium level >2 standard deviations above the mean. Corrected Calcium mg/dL =
 [0.8*(4.0g/dL - Patients Albumin g/dL)] + Serum Calcium mg/dL (X of 8.6-10.5 is in
 normal range; formula accurate only if Albumin is in 3.2-4.6 range). 5) Current
 serious or unstable medical illnesses including cardiovascular (e.g. unstable ischemic
 cardiovascular disease), hepatic, renal, gastroenterologic, respiratory,
 endocrinologic, neurologic, psychiatric, immunologic, or hematologic disease and other
 conditions that, in the investigator's opinion, could interfere with the participant
 being able to safely take high-dose vitamin D for the 3.5 year study duration; or has
 a life expectancy of <4 years; 6) History of recurrent renal stones; 7) Unable to
 undergo MRI scanning (e.g. pacemaker, metallic implants, severe claustrophobia); 8)
 Subjects with a history of osteoporosis will be excluded if the Screening serum 25-OHD
 level is < 12 ng/ml. 9) History of chronic psychiatric illness (e.g. schizophrenia,
 bipolar disorder), any episode of major depression within last 2 years, or current GDS
 > 6, any recent suicide attempts or suicidal ideation; 10) history within the last 5
 years of a serious infectious disease affecting the brain (including neurosyphilis,
 meningitis, or encephalitis), or head trauma resulting in protracted loss of
 consciousness (>10 minutes) or any persistent cognitive deficit; 11) History of
 chronic alcohol or drug abuse/dependence as defined by DSM-IV, within the past 5
 years; 12) History within the last 5 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; 13) Does not have good venous access, such
 that multiple blood draws would be precluded; 14) Regular use of any of these CNS
 active medications: benzodiazepines, antipsychotics, narcotics, cholinesterase
 inhibitors, memantine or anti-epileptic drugs. Stable doses of SSRIs or SNRI
 anti-depressants will be allowed, and included persons will be discouraged to change
 the doses of any potentially CNS active medication throughout the 3.5-year study. 15)
 Those who plan to change their dosage of any vitamin supplement during the duration of
 the study may be discontinued from the clinical trial. Changes in vitamin supplement
 dosing (e.g. vitamin B12) will only be allowed if a specific deficiency has been
 found. If participants are taking vitamin D supplementation (e.g. in a daily
 multi-vitamin) at the time of screening, they should continue on this same dose of
 vitamin supplementation throughout the duration of the randomized clinical trial. 16)
 Current participation in any clinical trial involving experimental AD therapies
 (anti-amyloid, anti-tau, etc.). 17) Female subjects who are pregnant or plan to become
 pregnant during participation in this trial. 18) Inability to swallow oral capsules.

 -  We will not exclude subjects with stable coronary artery disease or vascular risk
 factors such as diabetes or hypertension, who otherwise meet our inclusion/exclusion
 criteria. We will allow inclusion of participants with prior TIA or prior history of
 one stroke, but will exclude those with past history of multiple strokes. We will
 allow participants with up to two incidental infarcts on structural MRI, because the
 presence of cerebrovascular disease is very common in any representative sample of
 U.S. elderly persons, and may be an important contributor to dementia and
 age-associated cognitive decline. We will not exclude those with severe white matter
 (WM) hyperintensities, for similar reasons.