Efficacy of different routes of vitamin B12 supplementation for the treatment of patients with vitamin B12 deficiency: A systematic review and network meta-analysis.

Background: This systematic review and network meta-analysis aimed to evaluate the three different administration routes of vitamin B12: oral, intramuscular (IM), and sublingual (SL) routes.

Methods: We searched four electronic databases (PubMed, Scopus, Web of Science, and Cochrane CENTRAL Register of Controlled Trials). We included only comparative studies.