An untreated vitamin B12 deficiency can lead to neurological problems or pernicious anemia, which occurs when your body doesn’t have enough B12 to produce the amount of red blood cells it needs.
Vitamin B12 shots are the most common way to prevent or treat a deficiency. The injections are prescribed by a doctor and given intramuscularly, or into muscle.
Injections are usually given as hydroxocobalamin or cyanocobalamin. These are very effective at raising blood levels of B12 and preventing/reversing a deficiency.
Bottom Line: If you are deficient in vitamin B12, then the injections are very effective at raising your blood levels.
Brain Function
Low levels of vitamin B12 have been linked to a decline in brain function.
Two recent reviews found that there may be a link between low blood levels and the development of dementia .
However, results have been mixed and treatment with vitamin B12 wasn’t effective at improving brain function in people with normal brain function .
Depression
It’s been suggested that there may be a link between low vitamin B12 levels and depression.
However, one review found that treating depression with vitamin B12 didn’t reduce the severity of symptoms.
Nevertheless, it was suggested that taking the vitamin on a long-term basis could help prevent a relapse into depression .
Currently, there is a lack of quality research in this area. Higher quality studies are needed to find out if there is a link between vitamin B12 and depression.
Osteoporosis
Osteoporosis is a disease in which the loss of bone mass results in weaker bones and an increased risk of bone fractures.
Interestingly, low blood levels of vitamin B12 have been linked with reduced bone mass .
Therefore, it’s been suggested that taking vitamin B12 may reduce your risk of osteoporosis. However, studies have provided mixed results