Hamza Ali Abir Abdalaal, Mohamed Fatima H A, Hago Samir, Elsadig Elgali Israa Fathelrahman, Sherfeldin Mohammed Hager Elsir, Mirghani Rania G
Internal Medicine, Maidstone Hospital, Maidstone, GBR.
Medicine, University Hospitals of North Midlands NHS Trust, Stoke on Trent, GBR.
Cureus. 2025 May 7;17(5):e83668. doi: 10.7759/cureus.83668. eCollection 2025 May.
Vitamin B12 deficiency is a well-recognized cause of neurological complications, including peripheral neuropathy, cognitive decline, and myelopathy. However, the extent of neurological benefits from supplementation, especially in subclinical cases, remains uncertain. This systematic review evaluated randomized controlled trials (RCTs) investigating the neurological effects of vitamin B12 supplementation. The review focused on treatment outcomes, route of administration, and population characteristics, along with the methodological quality of included studies. Ten RCTs were included, involving individuals with clinical and subclinical vitamin B12 deficiency. Supplementation improved neurological symptoms in patients with overt deficiency, with oral therapy showing similar efficacy to intramuscular injections, better tolerability, and lower cost. In older adults with subclinical deficiency, supplementation did not significantly improve cognitive or neurological outcomes. In diabetic patients with neuropathy, improvements were noted in symptom scores, but not in objective neurological measures. Although reductions in homocysteine levels were observed, these biochemical changes did not consistently correlate with clinical improvements. Vitamin B12 supplementation is effective for patients with clinical deficiency but shows limited neurological benefit in subclinical cases. Further trials using standardized outcomes and longer follow-up are needed to refine treatment strategies and support biomarker-guided approaches.
维生素B12缺乏是神经并发症的一个公认原因，包括周围神经病变、认知功能下降和脊髓病。然而，补充维生素B12对神经功能的益处程度，尤其是在亚临床病例中，仍不确定。本系统评价评估了研究维生素B12补充剂神经学效应的随机对照试验（RCT）。该评价关注治疗结果、给药途径和人群特征，以及纳入研究的方法学质量。纳入了10项RCT，涉及临床和亚临床维生素B12缺乏的个体。补充剂改善了明显缺乏患者的神经症状，口服治疗显示出与肌肉注射相似的疗效、更好的耐受性和更低的成本。在亚临床缺乏的老年人中，补充剂并未显著改善认知或神经学结果。在患有神经病变的糖尿病患者中，症状评分有所改善，但客观神经学指标未见改善。尽管观察到同型半胱氨酸水平降低，但这些生化变化与临床改善并不一致相关。维生素B12补充剂对临床缺乏患者有效，但在亚临床病例中显示出有限的神经学益处。需要使用标准化结果和更长随访时间的进一步试验来完善治疗策略并支持生物标志物指导的方法。
