I know the drill. 

You want to get healthier, so you’ve gone plant based…maybe even vegan. Super! And, there can be unexpected, silent, consequences, potentially detrimental to your health. 

When adopting a more nutrient-rich, plant-based lifestyle, your optimally known B12 sources quickly disappear, since B12 is produced in the bacteria found in the guts of animals and the soil they consume, especially chicken and cattle who have grazed off the land! 

You might be thinking, “whew” I’’m not vegan or vegetarian; I’m carnivorous, I’ve got this covered!”And that would be a logical thought, but please realize our mass-produced, factory farmed chicken and cattle are not out grazing or rooting around in the bacteria/B12 rich soil either, and even if they were, the pesticides for grasses kill B12 bacteria. The modern day scenario includes animals housed inside warehouses, eating GMO grains. Deficient B12 animals are not necessarily effective “carriers” for B12 in humans.

That’s right, think again, friend! Surprisingly, a study in Framingham, MA, found approximately one in six meat-eaters between ages 26 to 83 were B12-deficient, “not because people weren’t eating enough meat,” study leader Katherine Tucker said… “The vitamin (B12) isn’t getting absorbed.”

B12 deficiencies do not necessarily discriminate! A U.S. Department of Agriculture study found “Nearly 40% of the U.S. population are deficient in this nutrient.


Vitamin B12 can be stored in your liver for several years. This is important, because a change in diet might not always tip you off to the consequences. Instead, the onset of B12 deficiency symptoms might creep up slowly through several stages, and after a year or more of cutting animal protein from the diet, chances are you’re a bit shy of your recommended daily amounts of Vitamin B12 and starting the notice symptoms. Unfortunately, the lengthy timeline from food omission to symptom onset doesn’t always tip off the causation.

 Signs of B12 deficiency may include: 

  • Cognitive issues (memory and confusion)
  • Depression and mood issues
  • Nerve function (numbness and tingling)/nerve damage
  • Fatigue
  • Weakness
  • Constipation
  • Loss of appetite
  • Weight loss
  • Anemia

Sadly, as previously noted, these same symptoms can also coincide with age, so it becomes very easy to write off a B 12 deficiency to “I’m just getting old!” Seriously, I don’t know a single older person who doesn’t complain about their memory, joint pain, or fatigue! (It doesn’t have to be a dwindling quality of life either, but that’s a completely different blog for another day!)

With the scales tipped against you and with B12 being one of the most lacking vitamins in the diet, I recommend being more vigilant to include daily B12.

Drumroll,..the very best and safest source of B12 is through fortified foods (cereal, which I don’t recommend, because it typically packages GMO ingredients and added sugar) OR supplementation.  The individuals with the highest B12 levels aren’t meat eaters, they are the ones taking supplements, and “yes,” eating the most fortified breakfast cereal too!

Going Plant Based?…Add B12!

Have a less than ideal diet?… Add B12!

Not eating pastured, organic animal protein?…Add B12!

Yes, this is yet another reason I recommend supplementation is necessary in your modern day diet! As you might have already guessed, like everything, quality is king. So in this instance, I recommend an organic/nonGMO methylated B12, rather than the cyanocobalamin B12, which is both synthetic and contains trace amounts of cyanide (thus the name!)


While the usual sources of B12 include animal foods, meat, milk, egg, fish, and shellfish, their bioavailability rates in humans varies from a mere 9% (eggs) to 66% (chicken). So, you’d need to eat A LOT of these animal foods to gain the required daily allowance for B12. According to Dr. Michal Greger, with such a low absorption rate, you’d have to “literally eat hundreds of scrambled eggs a day. 200 to 400 eggs a day” with and added “69,000 milligrams of cholesterol—practically your entire year’s worth every day.”

As they say, there’s really no such thing as a free lunch. B12 comes with baggage, since animal proteins also package cholesterol, saturated fats, and are inflammatory to your cells. In this case, there’s no such thing as free B12!

Rather than animal foods, some (vegan or health-conscious) individuals rely upon algae, such as blue green Spirulina. While I love this amazing Superfood for its rich source of vegan protein and nearly all known vitamins, the B12 in Spirulina is considered an analogue, or a false B12, that is not made available in our bodies, AND it can interfere with true B12 metabolism. Nutritional yeast is another B12 source, which I highly recommend and is effective in a source available by your body. 

Right about now you should be wondering, so what IS the very best and safest source of B12?

In our more agricultural past, we had a great source of B12 from gardening and digging in the soil (picture soiled fingernails minus all the hand-cleansing and sanitizing methods) as well as from drinking dirty water sans uber filtration systems. I’m not gaming to move back in time, rather it’s critical to understand traditional B12 sources and how greatly they have been cut from our daily diet. The very soil remaining on our freshly grown veggies and the soil (and its bacterial residues) on our hands provided B12. (yes, there were clear benefits to a society less concerned with germs, disinfectants, and cleanliness!)

A change from farming to a more industrial society, a more plant-focused diet, B12 deficient food sources, medications that interfere with absorption rates (think beta and acid blockers as well as hormone replacement therapy and antibiotics), all coupled with an age-related inability to absorb B12 can contribute to B12 deficiencies.


B12 deficiencies are not exclusive to the plant-based eaters, yet detecting deficiencies is challenging…a silent epidemic levels not routinely tested by most physicians and with the low end reference levels at the lab. Many who might actually be deficient are rated in a “normal” range. 

And the deficiency can sneak up on you! B12 is slowly depleted, sometimes over the course of several years, so the symptoms can be masked as several other disorders. It’s truly best to test for deficiencies.

Physicians typically order blood count tests or blood B12 levels, but these can be unreliable tests since high folate levels can mask anemic symptoms of B12 deficiency.

Instead, more reliable B12 deficiency tests include:

  1. Blood homocysteine levels: an amino acid produced when proteins are broken down. A high homocysteine level usually indicate a B12 deficiency.
  2. Methylmalonic acid (MMA) testing, which is very sensitive to low B12 levels. 
  3. Specific urinary amino acids – These provide diagnostic information about unusual metabolism disorders involving vitamin or mineral deficiencies, including B12.


The B12 Recommended Dietary Allowance (RDA) for adults is 2.4 mcg per day, more for women who are pregnant or breastfeeding and less for children. Please don’t be fooled, however, with the average 5 mcg (men) and 3.5 mcg (women) daily vitamin B12 consumption since as noted, many are not absorbing this vitamin at that rate. It pays to test for a B12 deficiency and to determine proper supplementation.

Fortunately, B12 is water-soluble, so your body excretes excess amount of B12 through urine. Unlike our fat soluble vitamins, D, A, K, and E, this isn’t one that you’re likely going to overdo consumption; however I still do recommend consulting with a physician to validate levels with proper testing and dosing. 

To maintain your healthy, plant-based diet provides adequate B12, consider:

  • Eating fortified foods several times weekly to provide at least 3mcg daily.
  • Supplement daily with at least 10 mcg organic, methylated B12.
  • Supplement weekly with at least 2,000 mcg organic, methylated B12.
  • Consult with your physician for B12 tests and to confirm dosing.
  • Attend to symptoms of B12 deficiencies and don’t write them off to “old age!”