what is the side effect of b12 injection How Quickly Does Shot Work? Does It Help to Lose Weight? Understanding the B12 Vitamin Shot:

It works especially well in settings where speed matters and where alcohol or fentanyl use is a real concern

For references and more information , see the section on Pregnancy complications and adverse pregnancy outcomes in the Zinc article

NPs who prescribe metformin for an extended period, no matter the indication (eg, T2DM prevention and treatment, polycystic ovary syndrome), should consider B12 supplementation as well as perform routine measurement of vitamin B12 levels, both when starting metformin and at intervals of no more than one to two years thereafter (note that the optimal frequency has not been determined, and metformin can begin to decrease serum B12 levels in as little as three months).6 A recent study showed that clinicians initially prescribing metformin measure vitamin B12 levels less than half the time.10 In this study of 5,131 patients with T2DM who started taking metformin during a 5-year study period (2008-2013), only 44.5% had vitamin B12 tested

Others ask is vitamin D3 injection safe during pregnancy

Calabrese AT, Coley KC, DaPos SV, Swanson D, Rao RH

2015 Jan;69(1):1-2