Myths vs facts: B12 and blood sugar

Vitamin B12 and blood sugar: myths vs. facts. A common myth is that B12 directly raises blood sugar – it does not. Another myth is that only vegans are deficient; in reality, anyone with malabsorption, gastric issues, or taking metformin (a diabetes drug) can have low B12. Fact: B12 deficiency can cause fatigue and neuropathy, which may indirectly impair blood sugar management. Observational studies link low B12 levels with higher type 2 diabetes risk, but causality remains unclear. B12 supplements do not lower blood sugar, but correcting a deficiency can improve energy and nerve health. For people with diabetes or prediabetes, checking B12 status is prudent, especially if on metformin. Evidence is moderate – mostly from observational and mechanistic studies. Always consult a doctor before supplementing.