b12 injection webmd If your vitamin levels are low, shots and pills can help you with memory, trouble walking, and weakness. But they're not a general health boost for people with normal levels. Despite What Does Vitamin B12 Do?

The resorptionof vitamin B12 on the part of the gastro-intestinal tract is already limited in healthysubjects and dependent on the concentration of the intrinsic factor

In people without pernicious anemia, about 0.5 g/day of B12 is reabsorbed by enterohepatic circulation in which B12-containing bile is secreted by the liver into the digestive tract where the B12 is then reabsorbed via intrinsic factor

Once reconstituted, immediately withdraw the dose to be added to the appropriate intravenous fluids [see Dosage Information (2.2)] and discard any unused portion

It quickly provides the requisite energy, and is much more effective than vitamin B12 preparations in tablet form, which have to take a detour through the stomach and intestine

Vitamin B12 dosage recommendations and needs depend on your age and gender