1 General side-effects of hydroxo-B12 listed in the British National Formulary (BNF) are diarrhoea, dizziness, headache, hot flushes, nausea, skin reactions and urine discolouration
Low potassium causes exactly the symptoms people describe: muscle weakness, fatigue, cramps and sometimes palpitations
To check if B12 injections are working, you need lab tests to measure B12 levels
Based on UK guidelines and common practice, a GP surgery may refuse to give a B12 injection a day earlier than scheduled for a patient with Pernicious Anemia for a few key reasons: Clinical Guidelines and Protocols Standard Treatment Schedules: The NHS and professional bodies like the British Society of Haematology have established guidelines for B12 injections for Pernicious Anemia
The medication must remain refrigerated, so a cooler with ice packs is necessary for trips longer than a few hours