Foroughi Elaheh, Mozafar Mehrdad, Haghighi Shayesteh, Baerz Maryam Moghbel, Torabi Kosar Salehi, Bafti Aref Hafezi, Asadi Fatemeh, Askari Mani Khorsand, Shahabinejad Erfan
Student Research Committee, Isfahan University of Medical Sciences, Isfahan, Iran.
Division of Vascular and Endovascular Surgery, Department of Surgery, Shohada-Tajrish Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
BMC Neurol. 2025 Jul 1;25(1):262. doi: 10.1186/s12883-025-04268-4.
Bell's palsy (BP) is the most prevalent acute mono-neuropathy associated with facial nerve failure, accounting for 60-75% of all occurrences of facial paralysis. The primary pathophysiological mechanism leading to BP is recognized as the confinement of the facial nerve within the facial canal, caused by edema. The link between vitamin D and neurological disorders has drawn more scientific attention in recent years, and vitamin D plays a role as a neuro-immuno-modulator. While some studies suggest an association between vitamin D and the incidence of BP, others report no significant impact. This systematic review aims to critically assess the relationship between vitamin D levels and the severity of BP.
A comprehensive search was conducted across Scopus, PubMed, and Web of Science databases for articles published from inception until September 29, 2024. The inclusion criteria for this meta-analysis encompassed articles that reported serum vitamin D levels and vitamin D deficiency in patients with BP, compared with the control group, specifically those presenting original data from cross-sectional, case-control, and cohort studies. Vitamin D levels in BP patients were reported as mean ± SD. Meta-analyses were performed using Stata version 17 software (Stata Corp, College Station, TX), with effect sizes expressed as standardized mean differences (Hedges g) and 95% confidence intervals (CIs).
Three studies reported the mean vitamin D levels among BP subjects, with the pooled mean vitamin D level of 15.98 ng/ml (CI = 13.83-18.06). No significant difference was observed for grade 2 vs controls (Hedges'g = 0.05, 95% CI = [-0.38 to 0.49], P value = 0.79, I2 = 0%), and grade 3 vs. controls (Hedges'g = -0.18, 95% CI = [-0.55 to 0.18], P value = 0.32, I2 = 0%). In contrast, the meta-analysis showed a significantly decreased value for vitamin D across grade 4 of the disease (Hedges'g = -0.72, 95% CI = [-1.18 to -0.27], P value = 0.001, I2 = 0%).
In this systematic review and meta-analysis, we evaluate the relationship between serum vitamin D levels in patients with BP. Our meta-analysis showed a significant decrease in Vitamin D levels in patients with high-grade BP. Our meta-analysis results show that a high grade of BP is associated with lower serum vitamin D levels. Given that inflammation is involved in the pathophysiological background of BP, the anti-inflammatory effect of vitamin D can be a possible mechanism for the benefit of this vitamin in BP.
贝尔麻痹（BP）是与面神经功能障碍相关的最常见的急性单神经病，占所有面瘫病例的60-75%。导致BP的主要病理生理机制被认为是面神经因水肿而被困在面神经管内。近年来，维生素D与神经系统疾病之间的联系引起了更多科学关注，维生素D作为一种神经免疫调节剂发挥作用。虽然一些研究表明维生素D与BP的发病率有关，但其他研究报告没有显著影响。本系统评价旨在严格评估维生素D水平与BP严重程度之间的关系。
对Scopus、PubMed和Web of Science数据库进行全面检索，以查找从数据库建立到2024年9月29日发表的文章。该荟萃分析的纳入标准包括报告BP患者血清维生素D水平和维生素D缺乏情况的文章，并与对照组进行比较，特别是那些提供横断面、病例对照和队列研究原始数据的文章。BP患者的维生素D水平报告为平均值±标准差。使用Stata 17软件（Stata公司，德克萨斯州大学站）进行荟萃分析，效应大小表示为标准化平均差（Hedges g）和95%置信区间（CI）。
三项研究报告了BP受试者的平均维生素D水平，汇总平均维生素D水平为15.98 ng/ml（CI = 13.83-18.06）。2级与对照组之间未观察到显著差异（Hedges'g = 0.05，95%CI = [-0.38至0.49]，P值 = 0.79，I2 = 0%），3级与对照组之间也未观察到显著差异（Hedges'g = -0.18，95%CI = [-0.55至0.18]，P值 = 0.32，I2 = 0%）。相比之下，荟萃分析显示疾病4级患者的维生素D值显著降低（Hedges'g = -0.72，95%CI = [-1.18至-0.27]，P值 = 0.001，I2 = 0%）。
在本系统评价和荟萃分析中，我们评估了BP患者血清维生素D水平之间的关系。我们的荟萃分析显示，重度BP患者的维生素D水平显著降低。我们的荟萃分析结果表明，重度BP与较低的血清维生素D水平相关。鉴于炎症参与了BP的病理生理背景，维生素D的抗炎作用可能是这种维生素对BP有益的一种可能机制。
