No deviation, no substitution
Seek prompt medical advice if you experience: Severe or rapidly worsening joint pain that significantly impairs function or mobility A hot, swollen, very painful joint with fever this could indicate septic arthritis requiring SAME-DAY emergency hospital assessment Symptoms of severe allergic reaction after B12 injection (breathing difficulty, facial/tongue swelling, widespread hives, dizziness/collapse) call 999 immediately Systemic symptoms such as unexplained weight loss, night sweats, or profound fatigue Neurological symptoms including weakness, numbness, balance problems, or cognitive changes Symptoms affecting multiple joints simultaneously, particularly if symmetrical (both hands, both knees) Morning stiffness lasting more than 30 minutes , which may suggest inflammatory arthritis Your GP will conduct a thorough clinical assessment, including detailed history-taking and physical examination

Optimized B12 levels are especially helpful during periods of high physical stress or after illness when your body needs to recover faster and more completely
White blood cells are essential for fighting infections, so low B12 can leave you vulnerable to illness
Some MPs have said, I would need some compelling evidence to agree to do this. As if being restricted to just 4 lifesaving, cheap, injections a year isnt compelling enough