David Edelberg, MD

Before I present this guest post from physician David Edelberg on how Vitamin B-12 deficiency can cause “brain fog,” depression, and more, let me tell you how I first came to know him as a physician-sleuth who makes important connections.

“How could I not have known about adult ADHD before?” Dr. Edelberg remembers asking himself after attending a lecture in the late 1990s. When he related this story, I was interviewing him not about ADHD but about fibromyalgia. I had identified him as a national expert on this debilitating condition that seemed to be targeting the partners of adults with untreated ADHD in higher-than-average numbers. Dr. Edelberg had made the connection, too.

“Now, when my female patients talk about their life stresses, and I get enough clues about the husband, I’ll ask if he has ever been tested for Adult ADHD,” explains Edelberg, cofounder of an integrative medical clinic called Whole Health Chicago. Men living with an undiagnosed ADHD partner’s problematic behavior suffer stress, too, but some experts think that women are more biologically vulnerable to stress-induced maladies. “That’s because women lose the brain chemical serotonin much more quickly than men do, and replace it more slowly,” Edelberg explains. (I write more about this in my book. By the way, I hear from many women with late-diagnosis ADHD who also have fibromyalgia, often after decades of stress.)

Edelberg lays out program for fibromyalgia patients in his new book, Healing Fibromyalgia, following his book for women called The Triple Whammy Cure: the Breakthrough Women’s Health Program for Feeling Good Again in Three Weeks.

Finally, here is Dr. Edelberg’s guest post on B-12 Deficiency. It’s the first of “Six Commonly Missed Diagnoses” he’s addressing currently in his newsletter. Sign up here and/or visit the center’s Knowledge Base for more of his excellent articles.

Six Commonly Missed Diagnoses:

Part 1: B12 Deficiency

You’re pretty sure you know your body and you tell you’re doctor you’re just not feeling right. You’re tired, maybe a little depressed, a bit achy.  The list of foods you can’t seem to enjoy is definitely longer. Your doctor’s empathic, not at all dismissive of your symptoms, but after a physical exam and some apparently appropriate tests she can’t find anything really wrong.

On the surface, this is reassuring. After all, the main reason we do go to doctors is to ascertain that nothing serious is going on. Still, could she be overlooking something? After decades of treating patients with longstanding but undiagnosed chronic symptoms, here’s the first of six overlooked diagnoses I see most frequently in our patients at WholeHealth Chicago (for the subsequent five, sign up for Dr. Edelberg’s newsletter here and/or visit the center’s Knowledge Base for more health information): Vitamin B-12 deficiency.

One of the eight B vitamins, B-12 is involved in the metabolism of every cell in your body. Years ago B-12 was called “maturation factor” because cells need B-12 to mature from being young and ineffectual whippersnappers to fully functioning and mature.

B-12 deficiencies affect three major systems in your body: your blood, nervous system, and, less often, gastrointestinal tract. These three are targets because their cells either have a high turnover rate (blood and intestinal lining) or need a lot of B-12 to function smoothly (nervous system). The symptoms of low B-12 levels are related to each of these areas.

•    Low B-12’s effect on your blood is a specific type of anemia called megaloblastic anemia (as distinct from the more common iron deficiency anemia). A megaloblast is an immature, undeveloped red blood cell, large and bulky (megalo=large, blast=immature form). Remember, B-12 is needed for this cell to mature, so with insufficient B-12 megaloblasts accumulate in your blood. Symptoms are the same as for anemia from any cause, including fatigue, breathlessness, and lightheadedness. Your skin becomes a pale yellow, most likely because the red cells that do make it to maturity are very fragile and easily broken, releasing their yellow bilirubin pigment.

•    In your nervous system, B-12 deficiency causes symptoms affecting your nerves (numbness, tingling, tremors, balance problems) and your mind (depression, brain fog, mood swings, and, in rare cases, hallucinations and psychosis).

•    In your gastrointestinal tract, you might experience digestive symptoms and weight loss because you’re not absorbing food efficiently.

The irony is that with all these there’s usually just one predominant symptom, and making a connection to low B-12 can easily be delayed until other symptoms start to appear. For example, if your only symptom is tingling in your hands, you might undergo all sorts of diagnostic tests before your doctor thinks “Maybe we should check her B-12 level.”

What Causes B-12 Deficiency?


The list of causes is lengthy, but by far the most frequent culprit is a dietary one. Vegetarians who aren’t paying attention to the B-12 in their food choices will have downward-drifting B-12 levels, and virtually all vegans not taking Vitamin B-12 supplements ultimately develop deficiencies. Even the various vegan organizations acknowledge it’s not possible to get adequate B-12 while following a strictly vegan diet, and that’s because the richest sources are animal products.

Other causes of B-12 deficiency include pernicious anemia, an uncommon autoimmune disease that destroys parietal stomach cells. These cells produce a substance called intrinsic factor, necessary for B-12 absorption. Also, since you need stomach acid to absorb B-12, long-term use of acid-suppressing proton pump inhibitors (Nexium, etc.) can lead to B-12 deficiency, as can chronic intestinal conditions like Crohn’s disease, celiac disease, and intestinal parasites.

Danger of This Missed Diagnosis


The main danger of missing this diagnosis is that (while quite rare) the damage to your nerves and even brain can be permanent. Other serious consequences: your anemia can get so severe it causes heart failure and collapse. Or you could be misdiagnosed with a major depressive disorder or even psychosis and take unneeded psychiatric medications for months (or years) before someone notices you look yellow-ish and you’re finally diagnosed with megaloblastic anemia.

There are four reasons why this diagnosis is missed:

1. Although it’s not an expensive test, B-12 isn’t measured during routine blood tests. Doctors generally don’t order a B-12 evaluation if there’s no evidence of anemia (which would be picked up on a routine blood test). However, the fatigue and nervous system and gastrointestinal symptoms can precede anemia by months.
2. Doctors rarely ask (and patients rarely volunteer) information about their eating habits. In medical school, we’re taught that the U.S. diet is “plenty good enough to prevent any vitamin deficiencies.” To which I now respond, “Ha!” I agree most of us eat plenty of food (obesity levels are still on the rise), but it’s often food whose nutritional value has been castrated. Also, all vegetarians and vegans should be regularly tested for possible B-12 deficiency, but if your doc doesn’t know your eating habits you won’t be tested.
3. Like many blood tests, there’s considerable disagreement about normal levels of B-12. Most labs test B-12 levels between 200 pg/ml (picograms per milliliter) and 800 pg/ml. Someone at 250 pg/ml would be classified as normal, but symptoms can start appearing at 350 pg/ml. In Japan, normal B-12 was recently raised to 500 pg/ml and higher. We’ll see this type of erroneous overreliance on “normals” in other frequently missed diagnoses, like hypothyroidism, vitamin D deficiency, gluten intolerance, adrenal fatigue.
4. Taking the B vitamin folic acid (folate) or eating a lot of folate-containing foods without adding B-12 can actually mask the symptoms of a developing B-12 deficiency. Although folate will keep your blood count normal even if your B-12 is falling, the folate will not protect your brain and nervous system. You’ll have no evidence of megaloblastic anemia (because of the folate), but your symptoms of numbness, tingling, balance problems, and emotional issues will continue unchecked. By eating so many folate-containing green vegetables, beans, and lentils, vegetarians and vegans inadvertently mask their own slowly developing B-12 deficiency.

Treatment Is Easy

It’s virtually impossible to take too much B-12 as any excess of this water-soluble vitamin is eliminated via urine. Nutritional guru Alan Gaby, MD, has commented that the only way too much B-12 will kill you is if you fill your bathtub with it and drown.

Foods high in B-12 are animal products: meat, poultry, seafood, dairy, and eggs, with eggs having the least. Because all animals store B-12 in their livers, eating liver is an excellent (though not particularly popular) treatment for B-12 deficiency. Your grandmother or great-grandmother likely remembers a time when her doctor told someone in the family to eat more liver.

And since people with low B-12 are likely to also have gastrointestinal symptoms that interfere with B-12 absorption, the best way to quickly increase (and maintain) B-12 levels are with B-12 injections, chewable tablets, or the recently released nasal sprays and skin patches.

In my own practice, a deficient patient receives a series of four B-12 injections (or four B-12 containing Meyer’s Cocktails) and also starts (and maintains herself on) a daily B-12 chewable tablet. Usually within a month her levels are back to normal.

There’s more to come in the Commonly Missed Diagnoses series. Next week: overlooked diagnosis #2, vitamin D deficiency/ (for the subsequent five, sign up for Dr. Edelberg’s newsletter here and/or visit the center’s Knowledge Base for more health information)

Be well,
David Edelberg, MD

Dr. Edelberg, board certified in Internal Medicine in 1974, began incorporating alternative therapies into his practice during the 1980’s. Since founding the parent company of WholeHealth Chicago in 1993, he has become nationally recognized as one of the pioneers of integrative medicine, a new specialty combining conventional medicine with alternative therapies. He is the author of two books and numerous articles and is the editor of five books on integrative medicine;