Foods rich in vitamin B12 include unprocessed meat, eggs, and dairy products, per Healthline
It was lethal, until doctors found a way to get B12 into the bloodstream
Contact your GP if you experience: Unexpected symptoms after starting B12 supplementation, including persistent skin reactions, gastrointestinal disturbance, or mild allergic manifestations Neurological symptoms such as significant tingling, numbness, weakness, or balance problemsthese may indicate B12 deficiency paradoxically, or alternative neurological conditions requiring assessment Unexplained fatigue or malaise that develops or worsens despite supplementation Concerns about medication interactions , particularly if taking metformin, proton pump inhibitors, or other medications affecting B12 metabolism [2] [4] Seek emergency medical attention (call 999) if you develop signs of a severe allergic reaction following B12 injection, including facial swelling, difficulty breathing, or widespread urticaria
Vegetarians and vegans seeking to prevent deficiency rather than correct existing insufficiency may maintain levels with consistent oral supplementation