Vitamin B12

Vitamin B12 is an important vitamin that plays a role in neurological and muscular functioning. Deficiency, though rare, can lead to a number of diseases including megaloblastic anemia and neuropsychiatric conditions. B12 deficiency is rare in Canada and it is estimated that 5% of people are deficient [1].

What are the risk factors associated with B12 deficiency?

• Age > 75

• History of irritable bowel disease (IBD) (i.e. celiac disease, Crohn’s disease involving the small bowel)

• Had a gastric bypass

• Had removal of part of your small intestine

• Vegan

• Taking certain medications (i.e. pantoprazole, rabeprazole, ranitidine, metformin, or equivalents etc)

• Alcoholism

What are the symptoms of B12 deficiency?

Though rare, neuropsychiatric manifestations of B12 deficiency include:

• Numbness

• Insomnia

• Cognitive slowing

• Restless leg syndrome

• Weakness

• Balance and co-ordination trouble

• Difficulties with memory

• Depression and irritability

If my B12 levels are low, do I need B12 injections?

There is strong evidence that oral B12 supplements are absorbed equivalently to injectable B12 to restore normal serum concentrations. B12 injections are, in fact, rarely recommended in treating B12 deficiency. Specific circumstances would be when a person has significant neurological symptoms or has a diagnosed gastrointestinal disease that prevents the oral absorption of B12. B12 injections were used historically to treat patients with B12 deficiency but have fallen out of favour as there is limited evidence to support their use over oral medications.

I don’t have any risk factors - should I test my B12 levels?

Canadian practice guidelines do not recommend routine testing of B12 unless you have risk factors or potential symptoms of B12 deficiency.

References

[1] https://www2.gov.bc.ca/gov/content/health/practitioner-professional-resources/bc-guidelines/vitamin-b12

[2] https://choosingwiselycanada.org/wp-content/uploads/2017/09/Nurse-Practitioner.pdf

[3] https://www.mayoclinic.org/drugs-supplements-vitamin-b12/art-20363663