If we admit that vegans need to get vitamin B12 through fortified foods or supplements, are we saying that a vegan diet is unnatural?
One point to consider is that feces contain large amounts of vitamin B12, produced by bacteria in the colon, and that if we found ourselves in a state of nature, and still wanted to be vegan, we could get enough B12 from feces, though it would be important to make efforts to make sure the bacteria were killed and viruses were neutralized. Admittedly, that's not terribly appetizing.
People have told me that they and other vegans they know do not take vitamin B12 supplements nor eat fortified foods and are healthy. While many vegans do not supplement with B12 and remain apparently healthy for many years, they normally do not know what their homocysteine levels are, which could eventually contribute to stroke or dementia. They might eventually run into overt B12 deficiency (see Individual Cases of Deficiency). You are taking a real chance by assuming you have transcended the need for a recommended B12 intake.
As people live longer, homocysteine has more years to cause damage to the body. Because of this, the importance of B12 has increased. The longer a vegan does not supplement with B12, the lower their active B12 levels will drop, increasing their homocysteine levels.
In Western society today, it is easy for vegans to ensure an adequate B12 intake. Vegans who supplement with B12 can have superior B12 status to non-vegetarians who do not supplement. In fact, due to a decrease in the ability to absorb B12 from animal foods as people age, the Food and Nutrition Board says that all people (not just vegans) over age 50 should "meet their RDA mainly by consuming foods fortified with B12 or a B12-containing supplement."
Is the Vegan Diet Natural?
Is the vegan diet natural? To answer that question, I recommend an article that examines the subject in great detail, Comparative Anatomy and Physiology Brought Up to Date: Are Humans Natural Frugivores/Vegetarians, or Omnivores/Faunivores? by Tom Billings. After an extensive review of the research, Billings concludes that humans are not naturally vegetarians or vegans. Despite this, he says:
I am both pro-vegetarian and pro-[eating raw foods as a large portion of the diet]. Readers should be aware that I am a long-time vegetarian (since 1970), a former long-time (8+ years) fruitarian (also a former vegan),... However, I am definitely not a promoter of, or a "missionary" for, any specific diet. In reality, I am tired of seeing raw and [vegan/vegetarian] diets promoted in negative ways by extremists whose hostile and dishonest behavior is a betrayal of the positive moral principles that are supposedly at the heart of veg*ism.
You really don't need the naturalness claim to be a veg*n! That is, moral/spiritual reasons alone are adequate to justify following a veg*n diet (assuming the diet works for you, of course). Further, if the motivation for your diet is moral and/or spiritual, then you will want the basis of your diet to be honest as well as compassionate. In that case, ditching the false myths of naturalness presents no problems; indeed, ditching false myths means that you are ditching a burden.
Readers may also be interested in the article Humans are Omnivores, adapted from a talk by John McArdle, PhD (originally published in the May/June 1991 edition of the Vegetarian Journal). The PaleoVeganology blog also has interesting information about the diets of our ancestors.
Whose Diet is Really Natural?
I strive to be like my prehistoric ancestors in no way whatsoever. I am glad they were able to survive lives that were nasty, brutish, and short, in order to one day allow me to type away for hours a day on a MacBook. But I have already outlived them while eating a large proportion of food they wouldn't recognize and taking supplements both as a child and as an adult.
The idea that a prehistoric diet can be approximated today or that it would be the most optimal diet is rather questionable. Today's commercial plant foods and meats are different from the foods available in prehistoric times. We eat hybrids of plants and we feed foods to farmed animals that they would not normally eat. Farmed animals are typically given a host of supplements in their feed. The U.S. food supply is routinely fortified with a host of vitamins and minerals (such as vitamin D in milk), and most people who turn to what they consider to be a more natural diet as adults have often benefited from this supplementation. In the last two hundred years, nutritional science has solved all sorts of serious health problems that plagued humanity for eons.
Although there are exceptions, eating meat is one of the few things which most people try to do that is "natural." Paleolithic dieters are probably the most vocal anti-vegetarian, natural eaters. Yet they rarely eat insects, grubs, and worms which, according to Paleoveganology in his post What, No Bugs?!, "have long provided humans and other primates with nutrients, and continue doing so today in most parts of the world." So one has to wonder how close to nature they are actually trying to eat.
Future of Research on Vegans
Many vegans are understandably skeptical of the medical and scientific community. But by refusing to accept the scientific evidence in favor of the need to supplement with B12, we provide a steady flow of vegans with health issues for the medical community to study. If you are wary of the medical community, the best thing you can do is ensure that you do not develop B12 deficiency and become one of their subjects.
While I'm grateful that research has been done on vegans who do not supplement with B12, enough is enough. It is the vegan community's responsibility to stop this flow of research subjects. When researchers decide to do studies examining the health problems of vegans who do not supplement their diets with B12, it would be best if they simply could not find any.
Encourage New Vegans to Get B12
All vegan advocates should be aware of the symptoms of B12 deficiency (with the realization that elevated homocysteine levels occur long before these symptoms are noticeable), and the need for new vegans to start supplementing with B12 shortly after becoming vegan (or even near-vegan).