Continuous therapy was maintained once started, whereas intermittent therapy was stopped after glucose normalization and restarted only if needed. Key findingsAfter three years, type 2 diabetes developed in 11.5% of women receiving intermittent metformin and 11.1% receiving continuous therapy. Women receiving continuous metformin had a significantly higher rate of metformin-associated vitamin B12 deficiency than those on intermittent therapy (13.5% vs 3.7%). The researchers found that intermittent metformin provided diabetes prevention comparable to continuous therapy while reducing prolonged medication exposure and the risk of metformin-related vitamin B12 deficiency. The efficacy of intermittent metformin plus lifestyle intervention for diabetes prevention in women with prediabetes and prior gestational diabetes: a randomized clinical, non-inferiority trial.