A lack of amino acids such as glutamine not only damages the activation of effector T cells but also increases the number of Tregs, further highlighting the importance of maintaining sufficient glutamine concentration in the immune microenvironment [155]
Summary: Excessive vitamin B12 intake rarely causes toxicity, but very high levels from supplements or injections may be associated with skin reactions such as acne-like eruptions, though serious adverse effects remain exceptionally uncommon
However, recent research has suggested the drugs potential may be more diverse than just helping with diabetes treatment
You cannot get this vitamin from plant-based products, but only from animal sources such as dairy products, eggs, fish, meat, and poultry
Wade L, Neudorff L, et al