not for those sensitive to caffeine, pregnant/nursing women, or children under 18
How Often Do You Need a Vitamin B12 Injection
Seek medical advice if you are taking B12 supplements and experience: Persistent skin changes, particularly acne-like eruptions or rosacea worsening Unexplained headaches or dizziness that coincide with supplement use Gastrointestinal symptoms including nausea or abdominal discomfort Any allergic reactions such as rash or itching Call 999 or go to A&E immediately if you experience: Difficulty breathing Swelling of the face, lips, tongue or throat Severe rash or itching Other symptoms of severe allergic reaction after taking B12 These symptoms warrant review of your supplementation regimen

Conditions include alcoholic liver disease, viral hepatitis, cirrhosis, and primary or metastatic liver cancer Renal dysfunction : Impaired kidney function reduces B12 elimination, causing accumulation even with normal intake Haematological conditions : Myeloproliferative neoplasms, chronic myeloid leukaemia, polycythaemia vera, and hypereosinophilic syndrome increase transcobalamin production, elevating total serum B12 Laboratory interference : Macro-B12 (immunoglobulin-bound B12) and assay interference can cause spuriously elevated results without true excess In clinical practice, unexplained hypercobalaminaemia should prompt investigation for underlying disease, particularly in patients without obvious supplementation history
A healthcare professional should administer the injection
Owing to its importance in healthcare, bacteriostatic water for injection should always be kept in clinical settings in bulk