Should You Supplement B12 on a Raw Diet?

If you’re using a nutrition program to track your nutrients, you will inevitably notice that there are a couple nutrients lacking on a raw food diet.  An obvious one is vitamin D, which is covered in a previous blog, and of course, there’s the infamous vitamin B12 issue.

Let’s dig a little deeper to find out how this vitamin is involved in human health and why we as raw foodies might benefit from adding in a source of B12 to our raw vegan diets.


Molecular model of B12 put together by Dorothy Hodgkin via: London Science Museum

What is B12?

Vitamin B12, or cobalamin, is a water-soluble vitamin that is one of the many B vitamins that the body needs.  Although B vitamins share a common name, they are all chemically different and have different functions.  They are often found together in the same foods, but not always.  If you’ve also noticed the gaps between the numbers of B vitamins, this is because other B vitamins do exists and were once thought to be essential, but are no longer deemed as so.  Others are essential to other organisms and not humans.

B12 is responsible for brain and nervous system function and plays a role in the formation of red blood cells.  It can also play a role in DNA formation.  Needless to say, it’s pretty important!



B12 can only be made by bacteria, algae and fungi, whereas yeasts, higher plants and animals cannot synthesize it.  If a soil contains B12, there is a chance that the plant does have some B12.  If the plant comes in contact with animal manure it can also have B12 on the surface.  Other herbivores obtain their B12 from the nitrogen-fixing bacteria that grows at the roots and nodes of certain legume plants.

Human bacteria in the ileum can make some B12 as well, although it is unclear whether or not it is a sufficient amount to maintain good health.  B12 must be absorbed by the intrinsic factor in the ileum before it hits the large intestine (colon).  So despite the fact that human feces does contain considerable amounts of B12, it is unknown whether sufficient amounts have already been absorbed in the small intestine.  However, it is known that at least two species of bacteria – Pseudomonas and Klebsiella sp. – are capable of producing the vitamin in considerable amounts.


Deficiency Signs

The deficiency signs of vitamin B12 include macrocytic, megaloblastic anemia, and neurological symptoms due to demyelination of the spinal cord and brain and the optic and peripheral nerves.  It can also result in other less specific symptoms in levels just under the normal range such as sore tongue, lethargy, depression, poor memory, breathlessness, headaches, pale skin and weakness.  This damage can be irreversible once it occurs, especially when nerve damage is involved.

While 95% of the B12 deficiency seen in the United States is due to malabsorption issues, certain intestinal disorders, low presence of binding proteins, and use of certain medications, it is important to note that in some studies, vegans who do not supplement are often deficient in the vitamin.  Even in a study on raw vegans, 43 out of the 49 subjects showed levels lower than 221 pmol/L (300 pg/ml), with 6 subjects having levels less than 147 pmol/L (200 pg/ml).  Sub-clinical deficiency of B12 is considered to be between 148–221 pmol/L.  When the subjects took cobalamin sublingually they were able to increase their group mean MMA concentrations.

MMA concentrations as well as holoTC tests are the most accurate way to determine B12 status:

“Holotranscobalamin (holoTC) and methyl malonic acid (MMA) have higher sensitivity and specificity, compared with vitamin B12 determination, and are therefore regarded as modern biomarkers of B12 status. Total vitamin B12 as a marker results in underestimation of the prevalence of B12 deficiency.”

However, some raw vegans who consumed more sea vegetables and algae had higher serum B12 status than those who ate the same diet but did not consume these foods, suggesting there might be some benefit.


Where do Primates Get Their B12?

You might wonder then, how our close primate relatives gets their B12.  When you look at the primate diet, most meat advocates are quick to point out that chimps and other primates eat meat.  This is true and can work out to about 2-3% of the chimpanzee diet, while bonobos eat much less – one study placed them at the trophic level one below a species of antelope – making them very herbivorous in nature.

Despite its lower incidence, we cannot overlook this food source as a potential for B12 in the diet.  Chimps and other primates consume termites in quite significant amounts in their natural habitat.  In five different species of termites examined, all five had significant amounts of B12 in them.

Another possible source could be coprophagy, seen in many animals and to a lesser extent in nonhuman primates as another source of vitamin B12.  Feces can be a source of B12 for many animals held in captivity, but coprophagy has also been observed in their wild counterparts.

Of course, just being exposed to a variety of bacteria in the wild could provide some exposure to B12-producing bacteria as well.  Chimps and other primates are also known to consume dirt in their natural habitat as well, which could potentially have b12 bacteria in it.


Supplementing B12

It would be wise to take a B12 supplement as an insurance against the severe and irreversible deficiency effects of this vitamin.  The RDA for B12 has been set to 2 µg/day for the average adult, with 1 µg being the minimum required.  And since there are no toxicity effects of this water-soluble vitamin, the benefits definitely outweigh the risks for taking this supplement.  Alternate sources of B12, such as sea vegetables and algae, have not been sufficiently tested and could contain pseudovitamin B12, which could affect testing and your ability to absorb the vitamin.

Most supplements contain 1000 µg of B12 due to the capacity of most people to absorb the vitamin in its supplement form.  Cyanocobalamin and methylcobalamin are the most commonly found forms, as well as hydroxocobalamin.  Methylcobalamin occurs naturally in the human body, whereas cyanocobalamin and hydroxocobalamin are synthetic forms of the vitamin.

Check the labeling on your B12 to ensure it comes from a vegan source, as it can be derived from animal sources.


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