To assess the effect of Vitamin D (VitD) supplementation versus placebo on neurological and functional recovery in patients with acute ischemic stroke (AIS) undergoing physical therapy (PT).

VitD deficiency is prevalent in AIS and may impair neuroplasticity and rehabilitation outcomes. Supplementation could enhance recovery, but evidence remains inconclusive.

We systematically searched PubMed for randomized controlled trials comparing VitD supplementation with placebo in AIS patients receiving PT. Outcomes included NIH Stroke Scale (NIHSS), modified Rankin Scale (mRS), Barthel Index (BI), modified Barthel Index (mBI), Berg Balance Scale (BBS), and Functional Ambulation Scale (FAS). Mean differences (MD) with 95% confidence intervals (CI) were pooled using fixed- and random-effects models (DerSimonian-Laird).

Five trials (PMIDs: 29950783, 31181657, 32567290, 38011419, 38024000) were included. VitD significantly improved NIHSS at 3 months in the fixed-effect model (MD -1.21; 95% CI -1.80 to -0.61; p < 0.0001), but not in the random-effects model (MD -0.84; 95% CI -2.53 to 0.84; p = 0.32). Effects on mRS (MD -0.30; 95% CI -0.89 to 0.29) and BI (MD 0.63; 95% CI -3.03 to 4.28) were modest and inconsistent. Functional outcomes favored VitD: mBI (MD 8.85; 95% CI 7.93–9.77), FAS (MD 0.68; 95% CI 0.60–0.76), and BBS (MD 11.01; 95% CI 10.27–11.75). Heterogeneity was high (I² = 64%) due to variable dosing and follow-up.

VitD supplementation during the acute stroke phase, combined with PT, may enhance neurological recovery and improve balance and ambulation. However, evidence is limited by small sample sizes and methodological variability. Larger, standardized trials are needed.