A review of individual studies found that people with lower serum vitamin B12 levels are at a higher risk for depression
[DOI] [PubMed] [Google Scholar] 209.Zhao G, Souers AJ, Voorbach M, et al
Many patients with diagnosed deficiency find their symptoms significantly improve after targeted supplementation, with over 90% reporting positive changes within a few months of treatment
In diabetes, prolonged periods of elevated blood sugar levels can lead to nerve damage
The speed of response depends on factors including the severity and duration of deficiency, the presence of neurological complications, and individual metabolic differences
Injections are also great for people who have difficulty absorbing nutrients, as well as those with certain medical conditions like Crohn's disease