Vitamin B12 is a somewhat controversial topic among people who do not eat animal products. Some say it is possible to get vitamin B12 naturally from plant foods, other say supplements are required. But if you talk to anyone who has actually studied nutrition, especially Registered Dieticians who specialize is non-animal product or vegan diets the answer is simple: B12 is impossible to get from non-fortified plant based food.
B12 is an important vitamin because it is required for cell division and the formation of red blood cells. It also helps with myelin production which is the coating around your nerve fibres that actually makes message conduction down the nerve fibre possible. Without an adequate amount of B12 a person can develop anemia (megaloblastic anemia to be exact, which is just a fancy way of saying that the red blood cells didn’t form right and are a bit too big) or, in the worst case scenario, develop permanent nerve damage. Not ideal in either case.
Natural B12 is created in the digestive tracts of animals and humans. Sadly, we produce it in our large intestine so very little can actually be absorbed. Foods that used to be known for being good sources of B12, such as soy, tofu, and some sea vegetables, actually don’t have a bioavailable source of B12. They carry inactive vitamin B12 analogues which do not do the job of vitamin B12 and can actually block the effects of B12 in some cases. Even the foods that claim they contain active vitamin B12 may not be true carriers of bioavailable B12. It is actually impossible to know because our current testing has no way of differentiating between active and inactive B12. A study done in the 1990’s showed that it was possible for plant products to absorb small amounts of vitamin B12 from soil that contained human and animal waste (ewwww) but it actually didn’t matter because the amounts of B12 absorbed by these plants was so infinitesimal it wouldn’t actually have nutritional value.
It make take some time for your body to show clinical signs of vitamin B12 deficiency because your folic acid stores will take over the job. Amazing how our bodies can adapt and compensate…but only for a short period of time. Also, as we age our ability to absorb B12 decreases.
Basically what it comes down to is that regardless of your reasons, if you eliminate animal products from your diet, you either have to keep really good track of the foods you eat that are fortified with vitamin B or take a supplement. I’m not a big supplement advocate, and I fully encourage people to be open with their doctor about what they are taking. Interactions between supplements and prescription drugs are far more common than one would think. One easy example is garlic. Did you know that ethnic groups, such as Italians, require a smaller dose of ‘blood thinning’ or anticoagulant medication than other groups simply based on the abundance of garlic in their traditional dishes? Fun fact.
Some examples of foods fortified with vitamin B12 are nutritional yeast, some veggie ‘meats’, soy milk, protein bars, and for those UK and Aussie friends out there, Marmite and Vegemite. If you choose to go the supplement route, pills aren’t the way. If the supplement isn’t chewable or sublingual (dissolving under your tongue or a liquid) you really aren’t going to absorb very much. The current recommended daily intake of vitamin B12 for adults is 2.5-6 micrograms. Another fun little fact: vitamin B12 supplements are grown on bacterial cultures, never from animal products.
Sadly all of this information points to the fact that humans are not “naturally” strict herbivores. Robert Mason, who writes on the PaleoVeganology website, said “This touches on the issue of how vegans should handle the caveman argument. Many of us are tempted to strain credulity and torture the evidence to ‘prove’ humans are ‘naturally’ vegan. This is a trap, and one into which carnists (especially paleo-dieters) would love us to fall; the evidence isn’t on our side There’s no doubt that hominids ate meat. The argument for veganism has always been primarily ethical, and ought to remain that way. It’s based on a concern for the future, not an obsession about the past.” Well said, Mr. Mason, well said.