It is suggested to take two capsules a day
Anderson, M.E., Powrie, E, Puri, R.N
Treatment for not getting enough vitamin B12 Doctors give vitamin B12 shots to people who dont get enough of it in their diet or have trouble absorbing it because they have certain medical conditions

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