C.PotterC
Many patients have undiagnosed low b12 even before medication use, particularly among certain risk groups
It also noted that as B12 deficiency increased, so too did insulin resistance
Because anaphylaxis can progress fast, many clinics give injections where trained staff and emergency treatments, including epinephrine, are available
Some more sensitive compounds don't tolerate the benzyl alcohol preservative well and are better suited to preservative-free sterile water or saline, even though this typically means the reconstituted solution should be used sooner rather than stored for weeks
However, if you are a vegetarian and vegan, you may be interested in trying out other sources of vitamin B12, such as nori, shitake mushroom, and fortified foods