What does chromium do?
Chromium contributes to the maintenance of normal blood glucose levels and to normal macronutrient metabolism. It is the one nutrient here with a recognised role of that kind.
Can I take these alongside my medication?
Ask your GP, pharmacist or diabetes nurse first. Berberine and cinnamon in particular can interact with glucose-lowering medicines, so it is not something to start unsupervised.
How much cinnamon is useful?
There is no agreed figure, and Ceylon cinnamon is generally preferred over cassia because it is much lower in coumarin. Follow the pack rather than adding spoonfuls to food.
Is berberine safe to take long term?
It is usually taken in courses rather than indefinitely, and it interacts with a number of medicines. Worth discussing with a pharmacist before starting.