Hello, good day and I'm looking for advice. The issue of B12 is one of the most discussed topics among vegans. I have thoroughly reviewed a number of materials, your recommendations as well as others, but I am still slightly confused and unable to find a B12 supplement that contains less than 40 times the recommended daily allowance - that is, 100 micrograms per "serving" (day). Does a supplement exist that contains only the recommended daily allowance? How do you yourself, as a vegetarian and someone who does not use any supplementation, manage to obtain enough B12? Is it actually okay to take practically pure B12 in liquid form (200 micrograms) once a week, to do it systematically and regularly, not every day, as you suggested in response to my previous query, and thus meet the overall human requirement? I hope your answer will finally help me gain clarity. Thank you in advance and have a lovely day.

B12 in vegans is a real issue, and efforts to address it through supplementation in recent years have not been exemplary. It's essentially a textbook example of how the modern scientific approach in nutritional therapy works, built on a dogged attempt to walk the path of increasing the intake of a single isolated substance, even though this approach does not yield measurable results (another example could be folic acid supplementation aimed at reducing the occurrence of cleft palate and spine in newborns, or fortifying foods with iodine to prevent thyroid dysfunctions). Once you supplement one component, you have the opportunity to track its metabolism and assess the results, which, for example, is never precisely evaluated with a nutrient complex aiming to harness the potential of synergy.

However, the fact is that the metabolism of B12 is relatively well described, and no synergistic interaction with other nutrients is known so far; hence the emphasis on increasing doses or experimenting with different chemical forms of the substance. Standard recommended doses of B12 are mostly found today only in multivitamins, while specialized products represent high multiples of the RDA, prompting the user to question how far they are prepared to go in dosing (practical experiences show that B12 overdosing—often further supported by megadoses of other B complex vitamins—speeds up the overall energy production in the Krebs cycle and can result in the overfunctioning of certain organs—most commonly the pancreas and thyroid, which I encounter quite often).

Currently, it is still unknown why B12 supplementation in regular (and essentially even high) doses is ineffective compared to the standard intake of this substance from animal sources. I know several vegans who do not supplement B12, and even after 10 or 20 years of this lifestyle, they do not show any significant symptoms of deficiency, but statistically, these are exceptions, as the vast majority of vegans do suffer from this component deficiency (but they only discover it after some time, when the body's reserves of this substance are depleted, which takes several years).

I believe it's more advantageous within supplementation to adhere to principles of synergy, i.e., not to take isolated B12 but a B complex (the fact that these substances are referred to as B complex vitamins has its reason), preferably of natural origin (for instance, obtained through yeast extraction).

I would like to incorporate my personal experiences into the answer; the problem is that I have no issue with B12. Although I haven't eaten meat for 10 years, I'm not on a vegan diet—I conduct nutritional experiments on myself throughout my life, most often in connection with sports activity, sometimes attempting veganism, but these lasted 6-12 months. Despite attempting to train 4 hours a day during this metabolic acceleration process, I seemingly could not deplete my B12 reserves, as my body showed no signs of deficiency.

One needs to question in these matters whether mechanisms are involved in the metabolism of B12 that we are currently unaware of on a scientific basis (e.g., the activity of intestinal microbiota or the excessive antinutritional factors so typical of plant diets). Nonetheless, I certainly share your concern about using extremely high doses—I do not think it is a good direction.

Themes:  Supplementation   Vegetarianism