If you do have decreased kidney function and your doctor recommends methylcobalamin, you may need a much higher dose because its less stable, so be sure to ask them about whats best given your condition
Although they each have their roles, vitamin B12 works closely with another B vitamin, folate, for the proper function of the nervous system, production of healthy red blood cells, and in S-adenosylmethionine (SAMe), a compound that supports mood and immune function 1
Common adverse effects: Injection site reactions: Pain, redness, swelling, or bruising at the injection site are frequently reported
This is often referred to as a washout period
doi:10.1098/rsbm.2002.0011
In research models, elevated NNMT activity has been associated with: lower NAD levels, with downstream effects on mitochondrial energy production