Cobalamin is not obtained through strict vegetarianism and the body begins to lack it. For this, it is recommended for vegetarians to add it with different vit. preparations.
I think it’s really time to put an end to the panic surrounding the famous vitamin B12 forever.
Of all the claims about what vegetarians are supposed to be missing, this one is the most ideologically colored. Since this ideology can be extremely dangerous, both for vegetarians who accept it and for omnivores who blindly believe it, let’s take a closer look. First, some basic facts about this vitamin. There is only one source of this vitamin in nature, and that is bacteria. No plant, no animal can produce this vitamin, only bacteria can do that. And this vitamin can enter the diet only through one or another bacterial activity.
Herbivores get this vitamin by ingesting it through impurities in food (the vitamin can be found in the soil) or by adding it to their food subsequently through the action of bacteria in their guts. For humans, due to the high sterility of our food, none of these methods are practical, reliable, or sensible. However, we can produce any amount of this vitamin with the help of bacteria, so realistically there is no fear that this vitamin may be missing in the diet. So the interesting question is why, despite the fact that this vitamin is very easy to produce in large enough quantities, there are claims that this vitamin is missing if we do not eat meat?
The reason, as already mentioned, is solely in ideology. And this ideology dictates that any cultivation of bacteria for vitamin B12 that takes place outside the intestines of animals is “unnatural” and as
so “unacceptable”. It sounds ridiculous, but this same ideology “allows” a completely unnatural environment in which we raise chickens today to produce eggs for us or raise cows to produce milk for us. However, the cultivation of bacteria to produce B12, according to this ideology, is not “natural” and is therefore unacceptable. The illusion of this ideology is also fueled by the fact that e.g. egg produced with the help of hens, a concrete meal, while vitamin B12, produced with the help of bacteria due to its small size (about 3 mcg) as a stand-alone dish is not suitable, so it is mixed with any food. And because we add it to food, the ideology immediately labels it an “unnatural, artificial additive.” Of course, he deliberately ignores the fact that even in nature, in animals that eat plant foods, this vitamin is always only added (as an impurity or as a subsequent action of bacteria) and is never an integral part of the diet. Also, this ideology deliberately ignores the fact that without “unnatural” technology (cutting and other mechanical treatment, sterilization by heat treatment, salting, smoking, etc.) a person would not be able to eat meat, which this ideology describes as the only “natural” source B12. Like all other ideologies, this one is meaningless and serves a specific purpose. It is understandable that the meat industry and meat supporters are eagerly spreading it in the absence of real arguments. It is unfortunate that many vegetarians also take it, and completely unnecessarily look for “natural” sources of this vitamin in the form of some algae or similar things.
So if we look past this unnecessary, nonsensical and dangerous ideology (which, as we will see later, appears in a multitude of other excuses) then it is clear that vitamin B12 can in no way be lacking in a meat-free diet unless we consciously choose to we don’t want to include it in it. All of the vitamin B12 available today is of bacterial origin, as chemically produced B12 does not exist. Many foods already have this vitamin added, but you can add it yourself in any amount.
However, the story of this vitamin does not end here. Vitamin B12, found in milk, eggs and meat, is bound to proteins, while vitamin B12 is produced by bacteria in free form. This means that the absorption of “animal” B12 requires more metabolic steps than the absorption of the free form of B12. This fact is also evidenced by numerous studies  , which show that people with age increase the likelihood of B12 deficiency, even if they eat it in large enough quantities. B12 deficiency occurs because this vitamin is ingested in an “animal” form that is less well absorbed. At the same time, it is extremely important that consuming B12 in free form eliminates the deficiency in these people. So free vitamin B12 is, on top of everything, superior in absorption and much more suitable for humans than the vitamin found in foods of animal origin.
That the matter is very worrying is evidenced by the results of a study  which shows that up to 30% of people over the age of 51 are not able to absorb B12 from meat or. this ability is severely impaired. With age, this percentage only grows. However, it is not only the elderly who are exposed to this problem, all age groups have a problem with the absorption of B12 from meat    . However, virtually anyone with these problems can easily absorb vitamin B12 in its free form. This is where the extreme danger of the above-mentioned ideology emerges. This ideology spreads extremely misleading claims that only “animal” B12 is true, that meat is an “extremely good source of B12” and so on. And omnivorous people, in the mistaken belief that they get enough of this vitamin from meat, don’t even suspect a lack of it. Unlike omnivores, however, vegetarians who consume a much more suitable, free form of vitamin B12 for humans do not have these problems. Only vegetarians (vegans) are at risk, accepting the ideology of “unnatural” B12 imposed on them and avoiding this vitamin unnecessarily.
In developed countries, due to the above-mentioned serious health problems resulting from poor absorption of B12 from meat, the mandatory addition of free B12 to human nutrition is being seriously considered  . Of course, such a conclusion would strongly imply the above-mentioned ideology, as it would be a recognition that meat is not a good, and not at all reliable source of B12. The only reliable and good source for humans is the free form of B12, produced with the help of bacteria and added to food.
To conclude: Vitamin B12 is produced in any amount with the help of bacteria, so a meat-free diet can contain it in any amount. Therefore, there is no (non-ideological) reason why vegetarians should be deficient in this vitamin. In addition, studies show that those who rely on meat B12 are significantly more at risk of B12 deficiency due to poorer absorption of meat B12 than vegetarians who consume it in free form. So just the opposite as claimed at the beginning of this chapter. This, of course, means that even this claim is just an excuse based on ideology and untrue facts.
And scientific references:
 Practitioners’ Guide to Meeting the Vitamin B-12 Recommended Dietary Allowance for People Aged 51 Years and Older, Christina Ho, Gail P.A. Kauwell, PhD, Rd, Lynn B Bailey, PhD, Rd, Journal of the American Dietetic Association, Volume 99, Issue 6
 Is it time for vitamin B-12 fortification? What are the questions ?, Ralph Green, American Journal of Clinical Nutrition, Vol. 89, no. 2, 712S-716S, February 2009
 Is It Time for Mandatory Vitamin B-12 Fortification in Flour ?, Experimental Biology 2008, San Diego, CA, April 8, 2008.
 How common is vitamin B-12 deficiency ?, Lindsay H Allen, American Journal of Clinical Nutrition, Vol. 89, no. 2, 693S-696S, February 2009
 Malabsorption of food cobalamin., Carmel R., Baillieres Clin Haematol. 1995; 8: 639–55
 Cobalamin, the stomach, and aging., Carmel R., Am J Clin Nutr. 1997; 66: 750–9
 Heterogeneity of gastric histology and function in food cobalamin malabsorption: absence of atrophic gastritis and achlorhydria in some patients with severe malabsorption., Cohen H, Weinstein WM, Carmel, R. Gut. 2000; 47: 638–45