Yes indeedee, B-12 repairs those nerve sheaths. I don't recall what it's called, a disease of the sheath, myol . . . something. I don't eat much red meat and produce, well, someone really knows where it comes from, but I don't. After doing some poking around I found out about methylcobalamin. I'm delighted you know, not many do, including the pharmacy I go to, they don't know about, don't know it exists and don't even know they carry it! LOL!

As for your magnesium, is this related directly to your kidney function, or a secondary of some metabolic kink? Magnesium is a strange animal. Foods & beverages we consume deplete magnesium, sodas, alcohol and coffee- I can't live without it, I think. 80% of Americans have a mag deficiency, I don't know about the European population.
I remember Aquafina! Bottled water is a staple here and was a staple for me in Los ANgeles. I used to drink Arrowhead distilled water only. I got my minerals from food and vitamins. They freak out over here about distilled, they only use it for ironing clothes and say it's detrimental to drink it. Tap water has antimicrobials, antiseptics and heavy metals, it tends to be extremely high in calcium, it's really evident here as I use vinegar to break it down to clean it off of surfaces, so, imagine what it does to the arteries and kidneys. Tap for cooking anything that's a pour-off, except rice or a cereal. It's a really good thing your doctor dug into the numbers and became aware of this, it's very important.