Q: When should I get my vitamin B12 level checked?

A: While there are no formal guidelines, most healthcare providers agree that older patients should be screened for vitamin B12 deficiency.

Those most commonly at risk for B12 deficiency are older than 75, alcohol users, vegans or strict vegetarians, those who use histamine H2 blockers (e.g., Zantac, Pepcid) and proton pump inhibitors (e.g., Prilosec, Nexium, Protonix) and those who take metformin for diabetes.

Vitamin B12 deficiency can cause anemia, which affects how your blood transports oxygen to all the body’s cells. Rarely, it can affect white blood cell counts and platelets.

More significantly, the lack of B12 can impact nerve fibers, resulting in numbness and pain in the arms and legs. In severe cases, one might experience loss of balance and difficulty walking.

Ultimately, dementia-like symptoms set in and can cause short-term memory loss and the inability to think clearly.

A simple blood test can easily detect B12 deficiency. If your results are low, other tests might be needed to confirm the diagnosis.

Some health care providers recommend that B12 levels should be greater than 350 pg/mL – especially in geriatric patients. If you are in this age category, your doctor might not do additional testing before prescribing treatment.

Treatment carries almost no risk, since it is nearly impossible to overdose on B12. The body passes any extra B12 in the urine.

Treatment for vitamin B12 deficiency includes injections and over-the-counter B12 supplements. Studies show that B12 tablets have the same effect as B12 injections.

If your deficiency is severe, your physician might recommend injections, especially if you are suffering with numbness or pain.

A rare side effect from too much B12 is skin irritation, such as acne; however, it would take extremely large amounts of B12 injections to trigger this effect.

Preservatives in the supplement might cause mild side effects, such as nausea.

Ask your physician if you should be screened for vitamin B12 deficiency.

Dr. William Kyle is an internal medicine physician with Memorial Health University Physicians in Okatie.