The Link Between B12 Deficiency and Neuropathy

Could it be B12 Authors
Sally M Pacholok, RN and Jeffrey J Stuart, DO

A startlingly high percentage of people experience B12 deficiency that causes neuropathy, but comparatively few are diagnosed. According to authors Sally Pacholok, RN and Dr. Jeffrey Stuart, many patients with a variety of neurological and physical disorders may actually be suffering from an undiagnosed B12 deficiency. Why do so few doctors test for B12 deficiency, and what can patients do to safeguard their health? LoveToKnow spoke with Sally Pacholok to find the answers.

About B12 Deficiency

LTK: You mention in the book that B12 deficiency can mimic a wide variety of mental and physical conditions. Can you tell us more about that?

SP: B12 deficiency can mimic anything neurological or psychiatric because deficiency destroys the myelin that insulates the nerve cell. It does mimic dementia, as well as bipolar disorder, depression, neuropathy, and diabetic paresthesia. Anything neurological in nature should have B12 ruled out as part of the diagnosis.

LTK: Who is most at risk for vitamin B12 Deficiency?

SP: Older adults should be tested. At least 25 percent of elderly adults lack the intrinsic factor necessary for B12 absorption. Everyone should take at least 1000 mcg daily, starting at age 55, to prevent dementia. People who take proton pump inhibitors to treat gastric reflux disease are also at risk. These drugs stop parietal cells from excreting intrinsic factor, and over time can lead to B12 deficiency. Metformin is a medication used to treat diabetes, but studies on metformin show it does something to the ilium that can also cause B12 deficiency.

Anyone with an auto-immune disease, like lupus, Grave's disease or celiac disease is also at higher risk because some forms of B12 deficiency are auto-immune diseases and we know that having one form of auto-immune disease puts you at higher risk for others.

People with gastrointestinal diseases or malabsorption disorders such as Crohn's disease, or surgery to the ilium need to be tested or treated prophylactically. You need a working digestive system to absorb B12, so also anyone who has had gastric bypass surgery needs to have their B12 levels monitored ideally before and after the surgery.

Diagnosing B12 Deficiency that Causes Neuropathy

LTK: Why are so many doctors reluctant to test for B12 deficiency?

SP: Because there is a knowledge deficit among physicians and health care professionals, who are trained to look for other problems. B12 deficiency is a very well-known disorder - it's been written about for over a century. It is cheap to treat, and for that reason seems to have lost it's vote. If B12 can cause dementia there is no reason to treat patients with expensive pharmaceuticals. They are getting more education on these expensive drugs and it's kind of not really being explained despite being very well-known.

LTK: You also mention that most standard blood tests will not always result in a diagnosis of B12 deficiency, even if one exists. Why is that?

A form of B12 deficiency can cause anemia but the neurological manifestations well precede the blood manifestations. Enlarged red blood cells, or macrocytic anemia, is equated with B12 deficiency. But it was identified in the mid-18th century, and in 1872 a German physician coined the term pernicious anemia. It was called pernicious because it killed people, and a lot of people died from it, but the most interesting thing is that they somehow have concentrated on the blood picture and that's it. The basic premise is being missed. Doctors are trained to look for severe anemia with enlarged red blood cells, so if you don't have the anemia they tend to not attribute your neurological symptoms to B12 deficiency.

You also need to consider other factors when testing. Issues such as kidney disease and dehydration can lead to false elevations of serum B12. Published studies in the scientific journals show nearly 40 percent of adults have B12 levels in what they call the low-normal range. So I also feel we could be even more cost effective if we could just raise the lower limit from 220 to 450.

LTK: What kind of testing is needed to properly identify B12 deficiency?

SP: First, you should try to do at least a serum B12 test. The next step would be urinary and serum methylmalonic acid. Methylmalonic acid is specific for B12 and people who are B12 deficient have elevated methylmalonic acid levels. Also test for homocysteine, folic acid and B6, because these can mask blood symptoms of B12 deficiency.

What you need is a baseline serum B12 test and a good clinical exam by a physician, if the physician is well-educated in the risk factors. If a person falls below 450 and they are symptomatic, they should be treated.


Neurological B12 Deficiency Symptoms

LTK: What kinds of neurological symptoms should people be looking for?

SP: B12 deficiency attacks the myelin and spinal cord. If you have neuropathy, paresthesia or diabetes, testing is important. Look for:

  • Numbness, tingling or weakness in the arms, legs or trunk
  • Unsteady or abnormal gait
  • Dizziness
  • Tremor
  • Restless legs syndrome
  • Forgetfulness
  • Depression
  • Irritability
  • Paranoia
  • Psychosis
  • Post-partum depression or post-partum psychosis
  • Fatigue

All these neurological symptoms put people at a high risk of falling. Falling is the number one cause of injury in people over 65 and this is the same age group most at risk for B12 deficiency. Then we see hip fractures and people in a lot of pain, requiring hospitalization, lengthy rehabilitation or moving to a nursing home. By simply testing for B12 deficiency we could help this epidemic and increase the quality of life and longevity for these patients.

If you think you may be at risk of B12 deficiency that causes neuropathy, especially if you are experiencing symptoms, Ms. Pacholok recommends you contact your physician as early as possible. Do not begin supplementation on your own before you have had a complete physical evaluation and blood test, as this could alter the results of your testing. For more information on B12 deficiency, visit the Could it Be B12 website, B12 Awareness, or pick up a copy of the book online or at your local bookstore.

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The Link Between B12 Deficiency and Neuropathy