B12 deficiency mistaken for something else

Well, this is worrisome.

B12 deficiency, and insufficiency, can cause all sorts of symptoms that might seem vague, or that might be mistaken for something else. I came across two reports of this recently.

Is it B12 deficiency or MS?

In this case, a patient was diagnosed with MS and recommended to start taking a very potent drug. The neurologic symptoms sure looked like MS, but tests, including an MRI of the spine, indicated B12 deficiency. The key was something called “inverted V sign”. You can see what that looks like here in the top right image. By the way, this image is from a different case; the person in question was a vegan, and so would have had no B12 intake, unless she took supplements.

So, B12 deficiency or MS? This is not a trivial distinction! Both can create a laundry list of symptoms that range in severity and can be caused by other medical problems. But the treatments are drastically different. In one case, take a vitamin supplement. In the other, start taking one or more potent (and probably expensive) drugs indefinitely. So kudos to the neurologists who figured out what was really going on.

Is it psychosis-dementia-epilepsy? Or B12 deficiency?

In this case, a patient suffered through 5 years of progressively worsening cognitive decline and seizures, before anyone figured out he actually had B12 deficiency due to pernicious anemia. The possibility of B12 deficiency was not considered, because the physicians didn’t see the classic symptoms like anemia or enlarged red blood cells. The report states that the patient

had a remarkable neuropsychiatric recovery after vitamin replacement and psychopharmacological management


B12 insufficiency is a sneaky problem. Even at blood levels above the official “deficient” cut off (200 pcg/ml), neurologic symptoms can develop. And those symptoms can develop in the absence of adverse effects on red blood cells. Unfortunately, physicians typically limit their B12 assessment to red blood cell lab values.

I wrote about B12 extensively in “Food Wisdom for Women“. It’s a particular concern for older adults for several reasons:

  • less absorption due to decreasing stomach acid with age
  • disruption of absorption by common medications: proton pump inhibitors (for stomach acid and ulcers, various brand names) and metformin (for Type 2 diabetes, under various brand names)
  • lower intake due to lower intake of food sources: meat, poultry, fish, eggs, dairy foods. This can be due to changes in taste, chewing problems, cost or convenience. Vegan diets don’t have any B12; vegetarian diets may have very little.

Pernicious anemia is another cause of B12 deficiency, but it’s a much rarer problem than those listed above.

So should you start second-guessing your physician if you’re diagnosed with a neurologic disorder or cognitive decline? You should certainly have a discussion if you have any reason to suspect your intake or absorption of B12 is compromised. These are just two cases, but they’re 2 cases that were caught (eventually). They should serve as a warning that some medical conditions common in older people are not always what they seem.

Thanks to ConsumerLab for alerting me to these case reports.