Patients should contact their GP if they experience: Persistent fatigue, weakness, or lethargy that affects daily activities Neurological symptoms including numbness, tingling, or 'pins and needles' in hands and feet Memory problems, confusion, or difficulty concentrating Mood changes, depression, or irritability Glossitis (sore, red tongue) or mouth ulcers Pale or jaundiced skin Unexplained balance problems or difficulty walking Individuals at higher risk should consider proactive screening , including those following vegan or strict vegetarian diets, adults over 60 years, people with gastrointestinal conditions (pernicious anaemia, Crohn's disease, coeliac disease, or previous gastric surgery), and those taking medications that affect B12 absorption such as metformin, proton pump inhibitors, or H2-receptor antagonists
This mechanism becomes clinically important when using high-dose oral supplements (typically 1000 micrograms or more), as it can provide adequate absorption even when the intrinsic factor pathway is impaired
However, all observed effects derive from animal models and in vitro research systems
Minimize exposure to moisture
