Impact of the MHRA safety update on vitamin B12 testing and coding in metformin users: a retrospective primary care analysis

This study demonstrated that the release of the MHRA Drug Safety Update was associated with a modest but statistically significant increase in vitamin B₁₂ testing among patients prescribed metformin, paralleled by a smaller rise in testing within the general population. However, diagnostic coding practices did not change, suggesting limited translation of safety alerts into structured documentation. Further research is warranted to explore barriers and evaluate interventions to improve monitoring and coding compliance in primary care.