route of administration of vitamin b12 injection Best Site: Administering B12 Shots Vitamin B12 Injection Sites: All
Description
A.DiegelmanP.et al (2007)

Oral capsules and liquids must fight their way through stomach acids and liver enzymes, resulting in a microscopic absorption rate of only 1% to 10%

For US and the rest of the world, orders take between 7 and 10 working days.

competition for vitamin B 12 by intestinal parasites or bacteria

Our plasma b12 becomes depleted without having frequent injections and we become symptomatic very quickly

Since they show up gradually, they often get brushed off as part of life