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Supplements and metformin.

Glucose-lowering supplements, B12 depletion, and the additive-effect pairs to watch.

Metformin is the first-line oral diabetes drug and the most-cited example of medication-induced nutrient depletion. After a year or more of daily use, vitamin B12 levels fall in roughly 10 to 30 per cent of patients. Annual B12 monitoring is sensible; supplementation is straightforward if needed.

Several supplements have their own glucose-lowering effect and stack additively with metformin: berberine, alpha-lipoic acid, inositol, chromium, and bitter melon all have evidence here. Adding any of these without monitoring fasting glucose carries hypoglycaemia risk. None of them are excluded; they are pairs where home glucose monitoring at the start makes sense.

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For adults over 18. This tool gives evidence-graded information, not medical advice. Always discuss changes with your GP or pharmacist, especially if you take any medication, are pregnant, breastfeeding, or have a serious health condition.
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