Around 15% of the US population is deficient in B12, which can cause them to feel fatigued, irritable, and constipated.

You cannot overdose on vitamin B12 because it is a water-soluble vitamin, so any excess is excreted through urine.

Vitamin B12 is important for the health of your nervous system and your red blood cells. It can be found in many animal products and fortified foods. In the United States, about 6% of people under age ...

If you’re enrolled in Medicare, these shots will be covered by Part B if you have them at a doctor’s office or a clinic or Part A if you get them while hospitalized. If you have vitamin B12 deficiency ...