Vitamin B12 Deficiency | 40 Percent of Americans are at Risk

Forgetting names lately? Battling brain fog? Lost your “edge?” Don’t write it off to just “getting older.” It could be something as simple—and curable—as vitamin B12 deficiency.

Once thought to occur only in vegetarians or the elderly, suboptimal B12 levels are found in nearly 40 percent of Americans of all ages, according to the recent Framingham Offspring Study. That puts virtually everyone at risk.

What Does B12 Do?

Known as the “energy vitamin,” vitamin B12 is essential for many critical functions in the body, including energy production, DNA synthesis, and blood formation. However, B12 is most critically needed to form myelin, the protective “insulation” that surrounds nerve endings and helps nerves “talk” to each other efficiently.

Without adequate B12, myelin can break down and cause symptoms that mimic multiple sclerosis, depression, or dementia. Other common symptoms include poor memory and mental fogginess, loss of motivation, apathy, mood swings, low energy, fatigue, muscle weakness, soreness or redness of the tongue, tingling, numbness or crawling sensations in the arms, legs, or feet, lack of coordination, and hair loss.

Here are several real-life cases of B12 deficiency—out of several dozen—that I have treated in the past few years:

• Suzanne is a 57-year-old teacher who came to me worried that she was developing multiple sclerosis like her brother. She was experiencing “cramps” in her legs, along with numbness in her hands and feet while walking. Fortunately, low B12 was the cause and her symptoms disappeared within three months of starting B12 supplements.

• Bruce, a 52-year-old broker, had tried “everything” for his recalcitrant depression. His B12 tested low, and within days of beginning B12 supplements, his mood improved dramatically.

• Rob, a usually tireless globe-trotting reporter, felt unusually fatigued after completing a big project. He also felt uncharacteristically lacking in motivation. A B12 test showed a level of nearly zero. Within a few weeks of supplementation, his usual drive and energy returned.

Are You B12 Deficient?

Anyone can have B12 deficiency. The Framingham study found that taking supplements, eating fortified cereal, or drinking milk helps protect against deficiency, but interestingly, meat consumption does not. In my clinical practice, I find that many vegetarians who get plenty of milk and dairy still have low B12, so lacto-vegetarians should not feel they are protected.

If you are over 50, mainly vegetarian, have digestive problems, do not take vitamin supplements or eat fortified cereal containing B12 regularly, or you take 500  mg or more of vitamin C with your food daily (which blocks B12 absorption), you are at increased risk of B12 deficiency.

The best way to find out is to ask your doctor for a B12 blood test. Experts give various opinions on the “gold standard” test, but a simple B12 blood level will do.

Do keep in mind (and challenge your doctor if needed) that the low “normal” limit of about 200 pg/ml is not enough. Levels below 300 double your risk of Alzheimer’s disease and increase your risk of hearing loss with age. Children and teenagers with low B12 are at risk for reduced learning ability and intelligence. Your B12 level should be above 350 or 400 to be safe.

If you can’t afford a test, and do not have symptoms, you may simply take a supplement of 100 to 500 mcg per day, but do it regularly for effective prevention.

How to Replenish Your B12

Vitamin B12 is found naturally only in animal products, including dairy, and in certain seaweeds, tempeh, and nutritional yeasts. However, B12 in non-animal products may not be active in the human body and may even block the effects of active vitamin B12, so it’s safest not to rely on non-animal sources. Keep in mind that if you are deficient, it is not possible to correct it with food alone.

Fortunately, oral supplements are as effective for most people as getting shots. Methylcobalamin, the form naturally in your body, is preferable to the more prevalent cyanocobalamin tablets (which contain toxic cyanide, albeit in trace amounts). Over-the-counter B12 patches, sublingual tablets, and nasal sprays are available and may enhance absorption.

B12 deficiency is common today in all age groups, whether you are vegetarian or not. If you are at increased risk, take supplements regularly to prevent future health problems. If you have symptoms now, see your doctor for a check-up and blood test. B12 deficiency is preventable and treatable, and correcting a deficiency may be just what you need to perk up your memory, mood, and overall well-being.      

Nancy Lonsdorf, M.D., practices Maharishi Ayurveda and integrative medicine for women in Maharishi Vedic City, IA. Call (641) 469-3174 or visit

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