benefit of b12 injections Luminous Vitamin B12 Injections: Benefits and
Description
OMCL, Official Medicines Control Laboratory

For subcutaneous injection, the typical range is 250-500 mcg per day

2001 Oct;25(10):1442-9

[1] Although water-soluble vitamins are generally excreted through urine when consumed in excess, vitamin B12 is unique in that significant amounts are stored in the liver
