I have read the recommendations to take potassium supplements when starting B12 treatment to prevent potassium deficiency during the healing process. Is it really necessary to take a supplement or will food be sufficient (e.g. bananas contain at least 450 mg each - if I eat 2 per day, will this be enough to mitigate the risks of hypokalemia)? I read in another thread that people are taking around 1000 mg potassium per day so this is around 2 bananas. I always prefer food sources of nutrients rather than supplements, where possible. My last blood test had my potassium level at a healthy 4.3 mmol/l (3.5 - 5).