Medical conditions affecting absorption warrant particular attention : Pernicious anaemia : an autoimmune condition destroying gastric parietal cells, requiring lifelong B12 injections Gastrointestinal surgery : particularly gastric bypass, gastrectomy, or terminal ileum resection Inflammatory bowel disease : Crohn's disease affecting the terminal ileum impairs absorption Coeliac disease : untreated disease damages the small intestine, reducing B12 uptake Medication use : long-term metformin therapy (MHRA safety alert) or nitrous oxide exposure Symptoms suggesting possible B12 deficiency include : persistent fatigue, weakness, paraesthesia (pins and needles) in hands or feet, glossitis (sore, red tongue), mood changes, memory problems, or unexplained anaemia
A realistic goal given absorption constraints
Once reconstituted, they should be kept refrigerated at 2C to 8C and used within the recommended timeframe
Many report improved energy, reduced fatigue, better exercise capacity, and reduced carbohydrate cravings
Vitamin B12 is mainly found in animal-based foods such as meat, fish, eggs, milk, and dairy products