Comparison Between Different Intramuscular Vitamin B12 Supplementation Regimes: a Retrospective Matched Cohort Study

Background

The incidence of vitamin B₁₂ deficiency after bariatric surgery can range from 26 to 70 %. There is no consensus on optimal vitamin B₁₂ supplementation in postbariatric patients. The objective of this study was to compare three different regimes.

Methods

In this retrospective matched cohort study, we included 63 patients with methylmalonic acid (MMA) levels ≥300 nmol/L. Group A (n?=?21) received 6 intramuscular (im) vitamin B₁₂ injections including a loading dose, group B (n?=?21) received 3 im vitamin B₁₂ injections without loading dose and group C (n?=?21) received no im vitamin B₁₂ injections.

Results

The total post-bariatric patient population consisted of 14 males (22.2 %) and 49 women (77.8 %) with a mean current body mass index of 30.6?±?8.0 kg/m². There was no significant difference in vitamin B₁₂ and MMA levels between 3 groups at baseline. There was a significant difference in follow-up vitamin B₁₂ levels of group A compared to group B (p?=?0.02) and group A compared to group C (p?=?0.03). In the follow-up results, there is also a significant decrease in MMA levels of group A compared to group B (p?=?0.02), group A compared to group C (p?p?

Conclusions

In this study, a shorter injection regime is probably not sufficient to treat a vitamin B₁₂ deficiency. An injection regime with 6 injections recovered all vitamin B₁₂ deficiencies biochemically. MMA levels cannot recover spontaneously over time without additional im injection regime.