Vitamin B12: What You Should Know
Having enough B12 can make a big difference in how well you feel. Here are some quick facts about vitamin B12 that you should know about. Knowledge is power - especially when it comes to your health.
Dietary Sources
Animal protein like fish and meat
Dairy and eggs
Fortified foods and drinks (e.g. some soy-based meat substitutes and beverages)
Signs and Symptoms of Deficiency
Note: you don’t have to have all of these symptoms to have low B12 levels (you don’t even have to have any of these symptoms).
Fatigue
Abnormal CBC results with blood work – this is often the first way that a B12 deficiency is discovered
Heart palpitations
Tongue inflammation
Pallor
Changes in the skin like loss of pigment or darkening
Potential impacts on fertility
In more severe cases it can affect the nerves (numbness, tingling), cognitive function and memory
Who’s Most at Risk for Deficiency
Note: Even if you don’t check off anything on this list, you could still have a deficiency. Also, being at risk does not mean you will definitely have a deficiency.
Patients with stomach and colon issues (e.g. surgeries, auto-immune gastritis, inflammatory bowel disease)
Those using certain medications: metformin, some medications for GERD or stomach ulcers
Vegans and vegetarians
Adults over 50-75 years old
Patients with an H.pylori infection
Testing and Results
The “normal” level for B12 varies widely between countries and even depending on which lab you go to! Anything below 150-220 pmol/L could be considered low. But sitting right at the bottom of the normal range doesn’t feel great for many people. I usually like levels to be comfortably above the low end of the reference range.
Testing B12 isn’t excessively expensive. If your MD tests it, it’s usually covered by OHIP. If I test it, it’s either covered by your workplace/ private health insurance or it’s around $20 out of pocket.
Note that measuring B12 in the blood isn’t a perfect science. If your levels are normal or low-normal but a deficiency is still suspected, other testing may be warranted to confirm deficiency (i.e. testing methylmalonic acid or homocysteine). This extra testing is on the pricey side.
Supplements: Oral Versus Injection
In many cases oral supplementation is just as useful as injections. But injections can have faster results and some people only seem to respond to injections. I wouldn’t consider injections as first line in most cases.
I’m all about getting our nutrients from the diet over supplements but in the case of B12, absorption is often better via supplements than food. So if you’re deficient, supplements may be the way to go. Many B12 products come in a form that you dissolve under the tongue. We don’t know for sure if this is better than swallowing the pill.
How Long Until You Feel Better?
Many patients feel better within a week of taking B12 but just because you don’t, doesn’t mean you should stop taking it. It can take several weeks (even a couple months) for CBC blood test results to normalize and for symptoms to improve.