A Vitamin B-12 injection is used to treat a variety of conditions that result from a deficiency of vitamin B-12, according to MedlinePlus. An injection can be used proactively to counteract the deficiency of vitamin B-12 due to various illnesses, infections or medications.Continue Reading
The National Institutes of Health indicates that Vitamin B12 deficiency may be caused by conditions such as pernicious anemia, malabsorption of the vitamin due to certain diseases, infections or medications, or a vegan diet. B12 deficiency can cause anemia and permanent damage to the nerves.
The body absorbs vitamin B-12 from food, and the injections serve to supplement the levels of the vitamin that cannot be absorbed from food due to certain ailments, as MedlinePlus states. Vitamin B-12 is also important for preventing anemia and the resulting permanent nerve damage. Vitamin B-12 shots have also been used for weight loss because they boost energy and metabolism, but as Mayo Clinic points out, these effects only occur if there is already a deficiency of vitamin B-12 in a person's body.Learn more about Vitamins & Supplements