Adapted from Bass et al
Following endocytosis, the HoloTC complex is degraded in lysosomes and free B12 is released into the cytoplasm, via CblF (Rutsch et al., 2009) and CblJ ( This free cytoplasmic B12 undergoes a series of intracellular transport and modifications to enable two core enzymatic reactions: 1) adenosyl-B12 acts as a co-factor for the enzyme methylmalonyl-coA mutase that catalyzes the conversion of methylmalonyl-coA to succinyl-coA, thereby enabling restoration of tricarboxylic acid (TCA) cycle intermediates and 2) methyl-B12 enables methionine synthase in the re-methylation of homocysteine to methionine using methyl-tetrahydrofolate (MTHF) as a methyl donor, thereby enabling the vital biochemical pathways of the folate cycle and methionine cycle, facilitating the downstream synthesis of important compounds like DNA and RNA (Figure 2)
If needed, consider taking over-the-counter pain relief, such as acetaminophen, to help manage pain and reduce inflammation
B12 injections may be the better choice if you: Have severe, diagnosed B12 deficiency with neurological symptoms Have pernicious anemia requiring medical supervision Have had gastric bypass surgery affecting all absorption Prefer less frequent dosing and don't mind needles Have a medical condition requiring injectable B12 specifically Who Should Choose Oral Spray
Injection site irritation may increase slightly since you are adding a daily injection to your routine, but site rotation prevents this from becoming an issue
B-complex vitamins, including B5 and B6, play a role in creating neurotransmitters such as serotonin and dopamine, which are important for controlling mood and stress levels