side effects to b12 injections Why Do I Feel Worse After My Injection? Causes & Management – Bolt Pharmacy Vitamin B12 Injections Side Effects

Vitamin B12 Why it matters: Found naturally in animal foods, vitamin B12 regulates key metabolic processes in the body both directly and as a cofactor (or "helper molecule") for two enzymes (methionine synthase and L-methylmalonyl-coenzyme A mutase)

found only in foods of animal origin Foods that are high in vitamin B 12 (g/100g) include: Liver (2658) Beef and lamb (13 Chicken (trace) Eggs (12.5) Dairy foods (0.32.4) In normal humans the absorption of vitamin B 12 from foods has been shown to vary depending on the quantity and type of protein consumed

That extra step can prevent confusion between micrograms, milliliters, and total vial contents

There are some supplies needed for subcutaneous injection

PMID 25828519

This process can be slow and inefficient, and people with absorption problems may take in far less of an oral dose than a healthy person would