You're a strong candidate for B12 injections if you experience any of the following: Persistent fatigue that sleep doesn't fix Brain fog, forgetfulness, or trouble concentrating Low mood, anxiety, or stress that feels disproportionate to what's happening Weight gain or difficulty losing weight despite consistent effort Tingling, numbness, or weakness in hands or feet (signs of B12-related neuropathy) Frequent colds, slow healing, or post-COVID fatigue A plant-based, vegetarian, or vegan diet Age 50 or older (B12 absorption naturally declines with age) A history of gastric bypass, Crohn's disease, celiac disease, or chronic acid reflux Long-term use of metformin (for diabetes), proton pump inhibitors (Prilosec, Nexium), or H2 blockers (Pepcid, Zantac) An MTHFR gene variant or known methylation issue A history of B12 deficiency, pernicious anemia, or low folate Hormonal shifts: perimenopause, menopause, postpartum If you fit one or more of these, a vitamin B12 shot is one of the lowest-risk, fastest-acting interventions available

doi:10.1016/j.bone.2005.04.017
Vestibular Migraine and Tinnitus: A Challenging Narrative
If there is any uncertainty, a pharmacist should be consulted to determine the appropriate diluent
[43] [41] During pregnancy the placenta concentrates B 12 , so that newborn infants have a higher serum concentration than their mothers
For this reason, our 2001 B12 recommendations in What Every Vegan Should Know about Vitamin B12 were focused as much on keeping homocysteine levels low as on preventing the traditional B12 deficiency symptoms of blood and nerve abnormalities