Whipple observed that blood regeneration was poor in dogs fed cooked liver after chronic blood loss
after an intramuscular injection of 1,000 g of cyanoB 12 , about 150 g is ultimately retained in the body 15 Most vitamin B 12 -deficient individuals in the UK and other countries are treated with intramuscular vitamin B 12 , and vitamin B 12 replacement has been traditionally administered intramuscularly
However, injections administered solely for general wellness or energy enhancement purposes, without a documented deficiency, may be considered elective and usually are not covered by insurance
However, a significant gray zone exists between 200 and 300 pg/mL where patients may experience symptoms despite levels that appear technically normal
This is one reason the loading schedule is medically supervised rather than something to rush
Common side effects can include pain at the injection site, mild diarrhea, and itching