Further general information on the clinical pharmacology of cyanocobalamin vitamin B12 for intramuscular injection including contraindications and precautions Quality: B12 Direct works only with country of origin government licensed suppliers and have independently tested our vitamin B12 for quality and safety at Mrieux NutriSciences (Vancouver Canada)
Holmes MC, Carter RN, Noble J, Chitnis S, Dutia A, Paterson JM, Mullins JJ, Seckl JR, Yau JL
But they are life-saving in the long run
That is one reason longer phase 3 trials drew so much interest, since the ceiling had not announced itself yet
However, there are specific circumstances when patients should seek medical advice regarding B12 levels and related concerns