Vitamin B12

Support for the nervous system, red blood cell formation and energy metabolism

Vitamin B12 (cobalamin) is an essential vitamin with an important role in the normal functioning of the nervous system, the formation of red blood cells, DNA synthesis and energy metabolism.

Vitamin B12 deficiency can have different causes, from insufficient intake to digestive absorption disorders, and can lead to hematological changes and neurological manifestations.

When may intramuscular administration be recommended?

Intramuscular administration of vitamin B12 may be indicated, after medical assessment, particularly in:

• vitamin B12 deficiency associated with megaloblastic anemia
• Biermer's anemia (pernicious anemia) and B12 deficiency associated with autoimmune gastritis
• vitamin B12 deficiency caused by digestive malabsorption
• deficiency occurring after certain gastric or intestinal surgical procedures
• the presence of neurological manifestations associated with vitamin B12 deficiency
• situations in which oral administration is not appropriate or the response to it is insufficient

Administration is carried out intramuscularly, at the clinic, under medical supervision.

The indication, dose, frequency and duration of treatment are established individually by the doctor, according to the cause and severity of the deficiency, the clinical manifestations and the laboratory test results.

Scientific references

• National Institute for Health and Care Excellence (NICE). Vitamin B12 deficiency in over 16s: diagnosis and management. NICE Guideline NG239. 2024.
• Green R, Allen LH, Bjørke-Monsen AL, et al. Vitamin B12 deficiency. Nat Rev Dis Primers. 2017;3:17040. doi:10.1038/nrdp.2017.40.
• Shipton MJ, Thachil J. Vitamin B12 deficiency – A 21st century perspective. Clin Med (Lond). 2015;15(2):145–150. doi:10.7861/clinmedicine.15-2-145.