Journal of Neurology Research, ISSN 1923-2845 print, 1923-2853 online, Open Access
Article copyright, the authors; Journal compilation copyright, J Neurol Res and Elmer Press Inc
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Original Article

Volume 16, Number 1, March 2026, pages 30-39

The Role of Calcitriol (Vitamin D) as Neuroprotection and Prognostic Biomarker in Patients With Ischemic and Hemorrhagic Stroke

Figures

↓  Figure 1. Flow diagram of the study selection process for articles included in the systematic review and meta-analysis.
Figure 1.
↓  Figure 2. Risk of bias analysis. (a) Traffic-light plot of the risk of bias assessment using ROB-2, illustrating the bias risk results for the effect of vitamin D supplementation on neurological function improvement across each domain. (b) Overall risk of bias conclusion using ROB-2, summarizing the risk of bias regarding the effect of vitamin D supplementation on neurological function improvement. (c) Overall risk of bias conclusion using ROBINS-I, indicating the risk of bias for vitamin D levels as a prognostic biomarker in stroke severity. (d) Traffic-light plot of the risk of bias assessment using ROBINS-I, depicting the risk of bias for the analysis of vitamin D levels in stroke severity as a prognostic biomarker across each domain. ROB-2: risk of bias 2; ROBINS-I: risk of bias in non-randomized studies of interventions.
Figure 2.
↓  Figure 3. Analysis results. (a) Forest plot showing the effect of vitamin D supplementation on neurological function improvement compared to the control group. (b) Forest plot analyzing vitamin D levels in relation to stroke severity as a prognostic biomarker.
Figure 3.

Tables

↓  Table 1. Characteristics of Study Data on Primary Outcome (Effect of Vitamin D Supplementation on Neurological Function Improvement)
 
No.AuthorLocationSample sizeStudy designDiagnosisIntervention regimenControl regimenOutcome measurement tools
1.Acharya et al, 2022India325Randomized controlled trialIschemic stroke and hemorrhagic strokeSingle intramuscular dose of 600,000 International Units (IU) of vitamin DVitamin D not administeredScandinavian Stroke Scale (SSS) score
2.Hesami et al, 2022Iran570Randomized controlled trialIschemic strokeSingle intramuscular dose of 600,000 IU of vitamin D3Vitamin D not administeredThe Neuron-Specific Enolase (NSE) level, the National Institutes of Health Stroke Scale (NIHSS), and Barthel Index (BI)
3.Karasu et al, 2021Turkey76RetrospectiveIschemic stroke and hemorrhagic strokeWeekly oral dose of 50,000 IU for 4–12 weeks, with a total dose ranging from 200,000 to 600,000 IUVitamin D not administeredBrunnstrom Recovery Stage and Functional Ambulation Classification (FAC) score
4.Rezaei et al, 2021Iran60Randomized controlled trialIschemic strokeSingle intramuscular dose of 300,000 IU of vitamin DVitamin D not administeredNIHSS, modified Rankin Scale (mRS), and the Mini-Mental State Examination (MMSE)
5.Torrisi et al, 2021Italy40Randomized controlled trialIschemic stroke and hemorrhagic strokeDaily oral dose of 2,000 IU/day of vitamin D3 for 12 weeksVitamin D not administeredMontgomery-Aasberg Depression Rating Scale (MADRS) and Functional Independent Measures (FIM)
6.Narasimhan et al, 2017India60Randomized controlled trialIschemic strokeSingle intramuscular dose of 600,000 IU of vitamin D3Vitamin D not administeredSSS score
7.Sari et al, 2018Turkey64Randomized controlled trialIschemic strokeSingle intramuscular dose of 300,000 IU of vitamin DVitamin D not administeredBrunnstrom Recovery Staging (BRS), Functional Ambulation Scale (FAS), Modified Barthel Index (MBI) scores, and Berg Balance Scale (BBS)

 

↓  Table 2. Characteristics of Study Data on Secondary Outcome (Analysis of Vitamin D Levels in Stroke Severity as a Prognostic Biomarker)
 
No.AuthorLocationSample sizeStudy designDiagnosisAssessment of stroke severityAssessment of serum vitamin D levels
8.Afshari et al, 2015Iran72Case-controlIschemic strokeBrain computed tomographyEnzyme-linked immunosorbent assay (ELISA)
9.Aggarwal et al, 2022India200One-year prospective observationalIschemic strokeThe National Institutes of Health Stroke scale (NIHSS) and modified Rankin scale (mRS)Electrochemiluminescence (ECL) method
10.Alfieri et al, 2017Brazil286Case-controlIschemic strokemRSChemiluminescent microparticle immunoassay (CMIA)
11.Borowicz et al, 2023Poland80Randomized controlled trialIschemic strokeNIHSS, mRS, and Barthel index (BI)CMIA
12.Rad et al, 2021Iran140Bi-center cross-sectionalIschemic stroke and hemorrhagic StrokeNIHSS and mRSECL
13.Samarakoon et al, 2024Sri Lanka60Prospective case-controlIschemic strokeNIHSS and mRSELISA
14.Selim et al, 2019Egypt138Case-controlIschemic stroke and hemorrhagic strokeNIHSS and mRSELISA
15.Simon et al, 2024India86Prospective observationalIschemic strokeNIHSSChemiluminescence immunoassay (CLIA)
16.Turetsky et al, 2015United States96Retrospectively analyze prospectiveIschemic strokeNIHSS and mRSCLIA
17.Wajda et al, 2019Poland240Retrospective cohort studyIschemic strokeNIHSS and mRSECL
18.Daubail et al, 2012France386Observational cohort studyIschemic stroke and hemorrhagic strokeNIHSS and mRSHigh pressure liquid chromatography coupled with UV detection
19.Fahmy et al, 2019Egypt96Case-controlIschemic strokeNIHSS and mRSELISA
20.Kim et al, 2020South Korea328Single-center retrospective studyIschemic strokeNIHSSRadioimmunoassay kit
21.Park et al, 2015South Korea818Observational cohort retrospectiveIschemic strokeNIHSS and mRSLiquid chromatography tandem mass spectrometry
22.Tu et al, 2014China364Prospective cohortIschemic strokeNIHSS and mRSCompetitive chemiluminescent immunoassay on a calibrated Elecsys 2010
23.Wang et al, 2014New York326Prospective cohortIschemic strokeNIHSS and mRSThe E601 modular (Roche Diagnostics, Mannheim, Germany) with a calibration range from 3 to 70 ng/mL