sublingual vs injection b12 Efficacy of different routes of vitamin supplementation for the treatment of patients with vitamin B12 deficiency: A systematic review and network meta-analysis Vitamin B12 Injections vs. Supplements:
Description
B12 Dosage for Deficiency and Pernicious Anaemia When B12 deficiency is diagnosed, treatment dosages are substantially higher than maintenance levels

Vitamin B12 injection contains Cyanocobalamin or Hydroxocobalamin that helps maintain the right B12 levels in the body and gives the much-needed energy boost
For the most part, that guidance holds up

Nicotinamide N-methyltransferase regulates hepatic nutrient metabolism through Sirt1 protein stabilization

Rachmilewitz B, Manny N, Rachmilewitz M

You should take this medicine for as long as it is prescribed for you
