Are You Vitamin B12 Deficient?

A young woman in her twenties began to have numbness and tingling in both of her legs. The feelings increased in intensity over several months. Slowly, she began to feel unsteady on her feet and eventually started falling over. When she also lost control of her bladder and began peeing her pants at such a young age, she finally took herself to the doctor.

Her diagnosis? Vitamin B12 deficiency.

The young woman was lucky. Supplementation reversed her symptoms, but not everyone is so fortunate. In many, the neurological damage is irreversible.

If you are vegetarian or vegan like many serious yogis, theres a good chance you might be vitamin B12 deficient, too. In a UK study last year, 52% of vegans and 7% of vegetarians were found to have deficient levels. Another 21% and 17% of vegans and vegetarians, respectively, had a serum vitamin B12 at the borderline low level.

Reprinted from J Med Case Reports. 2011; 5: 166.

That borderline level can be dangerously deceptive. Weve learned that tissue levels of B12 can be too low even when blood levels appear to be okay. Anyone with a borderline level needs to have another test or two looking at B12 function to determine whether or not they are getting enough of this important vitamin.

Unfortunately, it seems we non-meat-eaters arent paying enough attention to vitamin B12. Only 19% of those in the UK study reported taking a regular B12 supplement.

Among supplement users, 11% of vegetarians and 37% of vegans didnt meet the average daily requirement for vitamin B12 intake. That means even the supplement takers in the study werent getting enough of this important vitamin. Maybe thats because their supplements contained an inactive plant-based form of B12. We now know that this form is not only ineffective, but it also interferes with the absorption of naturally occurring B12 in food. If youre taking the wrong B12, youre not only not helping yourself, youre hurting yourself.

Vitamin B12 is crucial for brain cells and the tissues supporting all nerves. Its important for DNA synthesis and the synthesis of some brain chemicals involved in mood disorders and memory. Vitamin B12 is needed to make blood cells and low levels can cause anemia and troubles with immunity. Anemia is usually a late manifestation appearing long after nerve troubles. The young woman above, for example, had completely normal blood counts.

Symptoms of Vitamin B12 Deficiency

Numbness and tingling in the arms, legs, feet, or hands
Clumsiness with difficulty handling utensils and dropping things
Memory problems
Difficulty concentrating
Difficulty walking
Dry vaginal and vulvar mucosa
Frequent vaginal yeast infections
Possibly abdominal pain and nausea

If youre vegetarian or vegan – even if youre taking a supplement and think you have it covered – consider getting a blood test for vitamin B12. If you have any of the symptoms listed in the table above, please dont waste any time.

The treatment is a high dose of the proper kind of B12 taken as a pill. Doctors used to give shots, but weve learned thats overkill and pills (the right ones!) work just fine. If youre found to be deficient, dont mess with the over-the-counter unregulated brands that might contain the ineffective plant-based form or a similar non-working analogue. Your doctor can prescribe prescription strength, guaranteed quality vitamin B12 to treat your deficiency and, with any luck, relieve your symptoms.

Next time well talk about ways to prevent vitamin B12 deficiency on a vegan or vegetarian diet.


  1. Gilsing AM, Crowe FL, Lloyd-Wright Z, Sanders TA, Appleby PN, Allen NE, Key TJ. Serum concentrations of vitamin B12 and folate in British male omnivores, vegetarians and vegans: results from a cross-sectional analysis of the EPIC-Oxford cohort study. Eur J Clin Nutr. 2010 Sep;64(9):933-9. Epub 2010 Jul 21.
  2. Herrmann W, Obeid R. Causes and early diagnosis of vitamin B12 deficiency. Dtsch Arztebl Int. 2008 Oct;105(40):680-5. Epub 2008 Oct
  3. Watanabe F. Vitamin B12 sources and bioavailability. Exp Biol Med (Maywood). 2007 Nov;232(10):1266-74.
  4. Dali-Youcef N, Andrès E. An update on cobalamin deficiency in adults. QJM. 2009 Jan;102(1):17-28. Epub 2008 Nov 5.
  5. Rabhi S, Maaroufi M, Khibri H, Belahsen F, Tizniti S, Berrady R, Bono W. Magnetic resonance imaging findings within the posterior and lateral columns of the spinal cord extended from the medulla oblongata to the thoracic spine in a woman with subacute combined degeneration without hematologic disorders: a case report and review of the literature. J Med Case Reports. 2011 Apr 27;5:166.

What about other natural sources of B12?

There is no naturally occurring form of vitamin B12 that works in humans except for that made by bacteria. Animals eat the bacteria and then store the vitamin in their meat, milk, and eggs. Plants make their own vitamin B12, but its a form we cant use.

Any kind of seaweed, chlorella, fermented soybean, or other plant-based source of vitamin B12 is NOT reliable.

Only bacteria produce the form of B12 usable by the human body. Plant-based vitamin B12 contains analogues that interfere with the absorption and function of the correct form of B12.

These analogues can also interfere with the blood test for B12 giving a false reassurance of adequate levels. If youve been relying on plant/algae/chlorella derived vitamin B12 and are resistant to taking a supplement, ask your doctor to test blood levels of MMA and/or homocysteine to get a better idea of your actual B12 status. MMA and homocysteine levels in the blood are markers of vitamin B12 activity, and they rise when B12 function is inadequate.

The only other option is supplementation with fortified foods or pills.

Yeast and soy products that are fortified with B12 from bacterial or synthetic sources can provide adequate levels if ingested in sufficient quantities. Be careful though, because many of these foods contain plant-based vitamin B12 that is actually an analogue and therefore detrimental. Read the label carefully.

Commercial breakfast cereals, at least those manufactured in the United States, are usually fortified with an appropriate form of vitamin B12. If you are eating at least a full serving every day of Kelloggs All-Bran with Extra Fiber or some similarly fortified (preferably low-sugar and high fiber) commercial product, then vitamin B12 intake may be adequate.

Yeast, breakfast cereals, and soy products fortified with B12 are not natural sources. They are fortifications and thus supplements and therefore exactly what you are getting from a pill except perhaps less reliable if you dont eat adequate amounts every single day.

What to do:

Repletion. If you have not had an abundant, reliable source of vitamin B12 for two months or more, go directly to the pharmacy and buy 1000 microgram tablets. Both cyancobalamine and methylcobalamine are fine. The first is more traditionally used and therefore better studied. It doesnt matter whether you take a sublingual preparation placed under the tongue or take a pill. Take one a day for a month. After this important repletion of vitamin stores, follow the minimum daily maintenance recommendations.

Minimum daily maintenance. To get enough vitamin B12 from naturally occurring vegetarian food sources, eat at least a full cup of naturally produced yogurt (preferably sugar-free with live cultures) or low fat cottage cheese every single day. A cup of yogurt provides the bare minimum amount of vitamin B12 (or probably not if you listen to the US RDA and other recent data suggesting higher levels are much better for health). Its also a good source of calcium and of probiotic bacteria to keep the gut healthy.

An alternative for those who dont like yogurt is to drink at least two cups of milk every day. Note though that some evidence suggests that two or more glasses of milk may increase the risk of developing prostate cancer and three or more may increase the risk of developing ovarian cancer.

Eggs cannot be your primary source of vitamin B12. The amount of eggs that would need to be eaten to maintain adequate vitamin B12 levels is unrealistic and dangerous from the perspective of saturated fat and cholesterol.

Cheese might be a good source of vitamin B12, but its also loaded with saturated fat and calories, especially the best tasting variety thats made from whole milk. Getting much of your vitamin B12 from cheese isn’t a good idea.

Consider eating fortified foods like commercial breakfast cereals or yeast preparations. Make sure you check the labels to ascertain you are getting at least the bare minimum of 1 or 2 micrograms daily without unnecessary additives, preservatives, high fructose corn syrup, or sugar. For the yeast preparations, check to see that a bacterial or synthetic source of vitamin B12 has been added and not a plant derived analogue.

Ultimately, the best alternative for vegetarians (and especially vegans) may simply be to take a vitamin B12 supplement containing 25 to 100 micrograms daily. Theres concern that when mixed within a multivitamin, some chemical reactions take place that decrease B12 availability. As long as the vitamin manufacturer is reliable and the dose is 25 to 100 micrograms, the supplement should remain adequate.

You can also take the prescription strength 250 microgram tablet containing only vitamin B12 every day. There is a maximum amount that can be absorbed through a specialized mechanism in the intestines with the rest expelled through feces. Taking the higher dose may counteract a rising incidence of problems with vitamin B12 absorption such as is seen with small bowel bacterial overgrowth and low stomach acid resulting from pills taken for GERD or as a consequence of aging.

The bottom line…

Vegetarian, particularly vegan, yogis need to consider taking a commercial B12 supplement. A daily low dose tablet taken with food is more reliable than sporadic intake from various supplemented foods like breakfast cereals, soy products, and yeast.

Anyone resistant to supplementation from food products or pills should ensure they are eating abundant amounts of dairy products, preferably low fat and low calorie varieties.

Eggs cannot be relied upon as a sufficient source of adequate amounts of vitamin B12.

Anyone eating the bare minimum of one cup of yogurt or cottage cheese per day without other supplementation should have their blood levels of vitamin B12 (and/or its function with MMA and homocysteine) checked at least yearly and with any subtle manifestation of deficiency. Dont forget that if youve been ingesting plant based B12 analogues, they can interfere with the accuracy of the test.

Vitamin B12 for Yogis

Im generally not an advocate for taking anything from a pill bottle. Medicines should be kept to a minimum. Vitamins and nutrients are best absorbed from wholesome food and not from a tablet.

When it comes to vitamin B12 though, I make an exception. Many vegetarian and vegan yogis are simply not getting enough. Consequently, theyre slowly and insidiously harming their brains and nerves and potentially increasing their risk for various cancers.

How much vitamin B12 should you get every day?

The absolute bare minimum is 1 microgram per day, the average amount lost from the body in 24 hours. The US recommended daily allowance (RDA) for most adults is 2.4 micrograms. Recent evidence suggests weshould be getting 4 micrograms every day to ward off subtle brain dysfunction like depression and memory deficits as well as to prevent serious morbidity like dementia and stroke.

Animal products contain relatively high-levels of bacterially produced, naturally occurring vitamin B12. Omnivores generally meet even the higher requirements mentioned above. On the other hand, yogis following traditional Yoga advice dont eat any form of meat including fish. That leaves them with only a few naturally occurring sources such as dairy products, which are recommended for consumption by the classic texts, and eggs. Beyond that, its supplements in the form of fortified foods or pills.

How can vegetarians get enough naturally occurring vitamin B12?

To reach the absolute bare minimum to replace the average 1 microgram lost from the body daily without some from of supplementation, you must be drinking or eating:

  • 2 cups of milk every day or
  • 1 cup of yogurt every day or
  • 1 cup of cottage cheese every day
  • 5 ounces of mozzarella cheese every day or
  • Any other form of cheese in adequate amounts or
  • 20 eggs every day or
  • A proportional mix of milk, yogurt, cheese and eggs

These values take into consideration the bioavailability of the vitamin within its source. For example, eggs contain a substance that inhibits absorption in the intestines. Although each egg contains 0.6 micrograms of vitamin B12, it is only 9% available, so the effective dose from eating one egg is only roughly 0.06 micrograms. The vitamin B12 within milk, cheese, and yogurt is only 65% bioavailable. Of the 1.5 micrograms in one cup of yogurt, only .98 micrograms gets absorbed.

To meet the higher safety standard of the US RDA, youd need to more than double the amounts of milk products and eggs listed above. The recommendations are based not on what is average (1 microgram per day), but on what would cover 98 or 99% of the population – because everyone isnt average. Were all a little different when it comes to the subtleties of physiology.

For the highest level recommendations according to recent research, 4 micrograms, youd have to quadruple the amounts on the list. Eight cups of milk, four cups of yogurt, 20 ounces of mozzarella cheese, or 80 eggs in a day – or any proportionate combination of them is definitely WAY too much!