Methylcobalamin is best, unless you suffer from Lebers hereditary optic neuropathy (1 in 30,000 to 50,000 people), where hydroxy B12 is safer
If they're guessing, you're gambling
Prepared vials should remain refrigerated between 2-8C and protected from repeated temperature changes
"I'd say maybe only a handful of people at most in the last 10 years have I ever actually thought would benefit from B12 injections." As to why some physicians would be needlessly prescribing B12 shots, he said, "It may be just habit
So, stick to food sources for your vitamin B6 intake
Link about "What to do next" if B12 deficiency suspected or recently diagnosed b12deficiency.info/what-to-