(P11-008-23) Efficacy of Different Routes of Vitamin B12 Supplementation for the Treatment of Patients With Vitamin B12 deficiency: A Systematic Review and Network Meta-analysis

Objectives: 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 followed the PRISMA statement guidelines when reporting this systematic review and meta-analysis. We searched four electronic databases (PubMed, Scopus, Web of Science, and Cochrane CENTRAL Register of Controlled Trials). We included only comparative studies. Cochrane ROB2, Newcastle Ottawa Scale, and Cochrane ROBINS-I tools were used to assess the risk of bias. We performed a frequentist network meta-analysis of aggregate data to measure network estimates for the relative outcomes. Moreover, we conducted a pairwise meta-analysis using a random effect model to obtain direct estimates for outcomes. All outcomes of interest were continuous, and the relative treatment effects were pooled as mean difference (MD) with 95% confidence intervals.

Results: Thirteen studies were included in the meta-analysis, with a total of 4275 patients. Regarding increasing vitamin B12 levels, the IM route ranked first, followed by the SL route (MD 94.09 and 43.31 pg/mL, respectively) compared to the oral route (least levels). However, these differences did not reach statistical significance owing to the limited number of studies.

Conclusions: All IM, oral, and SL routes of administration of vitamin B12 can effectively increase the level of vitamin B12 without significant differences between them, as thought in previous research. However, the IM route was the top-ranked statistically but without clinical significance. We found no significant difference among studied administrated routes in all other CBC parameters and homocysteine levels.

Funding Sources: None to declare