how to give cat b12 injection Transdermal for Cats: a a B12 Shot in Hind Leg Area Vitamin B12 Injection For Cats:

Ill update again

Zhu XJ, Lin YJ, Chen W, Wang YH, Qiu LQ, Cai CX, Xiong Q, Chen F, Chen LH, Zhou Q, Li JH (2016) Physiological Study on Association between Nicotinamide N -Methyltransferase Gene Polymorphisms and Hyperlipidemia

ATP-citrate lyase links cellular metabolism to histone acetylation

[4] However, consistently taking large amounts of vitamins from multiple sources could potentially increase the risk of side effects (for example, very high vitamin B intake from multiple supplements over time can cause neuropathy, and high niacin from many sources could affect your liver)

Consult your doctor before starting, and continue treatment for the duration advised by your doctor

So, the B12 in the serum is OK, but in the brain, it is low