40% of Americans have low-normal B12 levels

B12 deficiency is much more common than the conventional medicine establishment and general public realize. Data from the Tufts University Framingham Offspring Study suggests that 40 percent of people between the ages of 26 and 83 have plasma B12 levels in the low-normal range, a range at which many experience neurological symptoms.

Nine percent had outright deficiency, and 16 percent exhibited near deficiency.

Most surprising to the researchers was the fact that low B12 levels were as common in younger people as they were in the elderly.

B12 deficiency has been estimated to affect about 40 percent of people over 60 years of age. It can mimic the signs and symptoms of diseases that are commonly associated with aging such as Alzheimer’s, dementia, cognitive disorders, multiple sclerosis, Parkinson’s, and other neurological problems; mental illnesses such as depression and anxiety; cardiovascular disease; cancer; and low libido.

It’s entirely possible that at least some of the symptoms we attribute to “normal” aging such as memory loss, cognitive decline, and decreased mobility are at least in part caused by B12 deficiency.

B12 deficiency is often missed for two reasons.

  • It’s not routinely tested by most physicians.
  • The conventional serum B12 test that most doctors run only picks up a small fraction of people who are actually B12 deficient.

This test measures the total amount of B12 in the blood and does not rule out functional B12 deficiency, which means low levels of active B12. The low end of the laboratory reference range for serum B12 is too low. Many people who are B12 deficient have so-called normal levels of B12.

For example, the lab reference range goes down to 211 pg/mL in most cases, yet it’s well established in the scientific literature that people with B12 levels between 200 and 350, levels that are mostly considered to be normal in the U.S., may exhibit clear B12 deficiency symptoms.

In Japan and Europe, the lower limit for B12 is between 500 and 550, the level associated with psychological and behavioral manifestations such as cognitive decline, dementia, and memory loss.

Some experts have speculated that the acceptance of higher levels of normal in Japan and the willingness to treat levels considered normal in the U.S. explain the low rates of Alzheimer’s and dementia in that country.

In addition, more sensitive markers for B12 deficiency are now available, including methylmalonic acid, or MMA, and holotranscobalamin-2, or holoTC, although this is not yet widely available clinically in the U.S. sensitive and accurate for detecting the early stages of B12 deficiency.

Unfortunately, few clinicians are aware of them, and they are rarely used in clinical practice. You can’t find what you’re not looking for, so this is the real problem with B12. This is a serious problem because B12 deficiency can take years to become clinically evident, and the effects can be irreversible.

Screening for B12 deficiency is completely harmless and over treatment is hard to do because B12 is so safe to supplement with, whereas misdiagnosis is not because of the potentially irreversible neurological damage, which is completely preventable.

Primary Causes of B12 deficiency include:

  • Inadequate intake (common in vegetarians and vegans
  • Intestinal malabsorption due to low stomach acid
  • Celiac Disease
  • Crohn’s disease, or other gastrointestinal conditions
  • Pernicious anemia
  • Atrophic gastritis (caused by H. pylori infection)

The elderly is another population at risk.

H. pylori infection and chronic proton pump inhibitor use (Nexium or Prevacid) lead to low stomach acid, which decreases B12 absorption.

Remember, B12 deficiency is thought to affect up to 40 percent of people over age 60.

It’s not just the elderly who are at risk from proton pump inhibitor use. Anyone who regularly uses antacids can be susceptible to this effect, and that now includes a lot of people under 60 years of age.

Over 15 million prescriptions were filled for these medications in 2013, and the FDA in its infinite wisdom recently made omeprazole, or Prilosec, available over the counter in 2000.

This was soon followed by Prevacid becoming available over the counter. PPIs were only approved for short-term use of two weeks, but they are now taken for years or even decades.

Numerous studies have shown side effects, risks, and complications, but this has not affected their use. The next population at risk is those with digestive disorders that lead to malabsorption. This includes celiac disease, which blunts the intestinal villi and causes malabsorption of several nutrients, and Crohn’s disease, which causes inflammation of the terminal ileum in many cases, and the terminal ileum is where the intrinsic factor B12 complex is absorbed.

Finally, the diabetes drug metformin has been shown to deplete B12 levels, so if you or someone you know has been taking metformin for some time, you might want to consider getting tested.

Children and B12 Status

While kids are not at particular risk unless they fall into the other categories we’ve just talked about, the effects of B12 deficiency in kids can be particularly alarming.

Studies have shown that kids raised until age six on a vegan diet are still B12 deficient even years after they started eating at least some animal products. In one study, the researchers found a significant association between cobalamin status and performance on tests measuring fluid intelligence, spatial ability, and short term memory, with formerly vegan kids scoring lower than omnivorous kids in each case.

The deficit in fluid intelligence is particularly troubling, the researchers said, because it involves reasoning, the capacity to solve complex problems, abstract thinking ability, and the ability to learn.

Any defect in this area may have far-reaching consequences for individual function.

Now, I recognize that there are many reasons why people choose to eat the way they do, and I respect people’s right to make their own choices. I also know that, like all parents, vegetarians and vegans want the best for their children. This is why it’s critical for those who abstain from animal products to understand that there are no plant sources of B12, and that all vegans and most vegetarians should supplement with it. This is especially important for vegetarian or vegan children or pregnant women whose need for B12 is even greater than adults.

Things to Consider When Supplementing

There are two forms of vitamin B12 that you’re likely to come across – methylcobalamin and cyanocobalamin. Cyanocobalamin is much more common in multivitamins and B12 vitamins, but there are lots of strong arguments to replace this ingredient with methylcobalamin.

In short, Cyanocobalamin is the synthetic (less expensive) form of B12, while methycobalamin or adenosylcobalamin is the form that mimics nature more closely.

So if you're considering supplementing, make sure you are using the better (methylcobalamin) form.