Hi guys, I'm hoping someone can give me some advice or info regarding my recent experiences outlined below I've just recently developed mouth, throat, tongue, arm / hand and leg / feet numbness and muscle weakness after restarting daily methyl b12 sublinguals (at first 1000mcg now 3000mcg/day). It's really quite striking weakness and numbness, never experienced it before and I've been having other symptoms for over 20 years - it's especially bad at night and after activity, I wake up most nights with my mouth and tongue feeling completely numb. In addition to the Country Life 3000mcg methyl b12, I am currently also taking Thorne Basic Nutrients IV (4 capsules / day, which should provide around 667mcg of folinic acid and methylfolate). Since I realised potassium could be a problem I've been drinking about 500ml of coconut water a day and eating one or two bananas / day, which should give me around 1200mg of potassium and it has improved somewhat, but it's now been going for around 3 or 4 weeks. The numbness in arms and legs is usually minor now (still have weakness), but mouth, throat and tongue still pretty numb. I've also noticed a worsening in my skin, more acne etc. Also, I've been on a vegan diet for the past 3 years or so - I started on this diet to try to keep fat intake to a minimum after I had a bout of pancreatitis which developed into a sort of low grade chronic pancreatitis, which has required I take digestive enzymes with food, it's also led to a malabsorption problem being identified. No doubt this diet would have further reduced my b12 levels, which could possibly have led to more severe startup effects than I've experienced before (?) Back to the main point here - the numbness came on about 2-3 days after starting the b12 daily - I didn't know b12 could cause this, so at first I was pretty worried and went and got a lot of tests done - they all came back clear. Having done some reading though a few things stand out in the results and might be relevant here: serum potassium level was 3.9mmol/L, which is within normal levels, but then i read this from @Freddd: "For instance untreated hypokalemia with methylation startup can kick in as high as at least 4.3...". So maybe that 3.9 result is a worry. My corrected calcium seems pretty low at 2.26mmol/L (reference range is 2.25-2.65), ionised calcium is 1.22mmol/L. Serum phosphate was also pretty low at 0.9mmol/L (reference range .8 - 1.5). Serum b12: 534 Serum folate: 47.2 My pH also seems borderline low at 7.37 Creatinine Kinase was normal which apparently indicates no muscle breakdown, which seems like a positive. I've also recently started taking more salt to deal with my POTS symptoms, which may also be affecting my potassium levels (?) So I guess what I'm hoping to get more info about is: does this sound like a b12 startup reaction? if so, should I be doing anything other than increasing my potassium intake? do my test results indicate anything in particular that I should be doing differently? Sorry for the length of the post, just wanted to include as much (hopefully) relevant info as possible. I'd really appreciate any feedback / advice / ideas anyone can offer Thanks!