Hello, my name is Stelios Pantazis, I am a doctor specializing in Medical Nutrition and in metabolic disorders and today I would like to talk about B12. And in fact for the levels of B12 that are ideal for the blood and how we could examine that, as well, after many questions I have received on the subject through the channel, but also from customers coming to the my office. Before I get started I would like to ask you if you find the content interesting to press the like button, share it with people who will find it interesting, and use the comments to suggest topics for the next videos. So let's get started on vitamin B12. First of all, B12 is a vitamin that is relatively difficult to absorb. And why do I say that? Because a factor needs to be produced in the right amount in the stomach, and its absorption occurs at the end of small intestine, a place where several germs often develop sometimes coming from the colon and this often leads to difficulties in the absorption of B12. And that's why we can say that in people over 40, 1 in 4 do not have adequate levels of B12 in their blood. Of course, the issue is also how the blood levels are determined. And that's what we're going to talk about today. But before I get started, let me say again that the test we use to measure B12 measures B12 in blood and not in the cells, so you can't know if the B12 in the cells is sufficient only from measuring B12 in blood. Measuring something in the blood is like seeing the streets of a city and trying to assess how many cars exist in the city. Such are the results we get from a blood test. You will not see how many cars are parked in the houses etc. Considering these limitations, it's a bit difficult to draw absolute lines and to say that this is okay, this is not okay. What is certain, however, is that if someone has more than 350 vitamin B12 in their blood, they can be quite sure that the levels in their cells are sufficient. Also, those under 200 should be pretty sure there is a problem. The B12 in their blood is low. They have to make some decisions and take some measures. There is a large part of the population that exists in the gray zone between 200-350. Let's say there is someone with an answer between 200 and 350. What can one do? The simplest solution is to start taking dietary supplements with B12, the ones you will find at the pharmacy, the simplest, the most economical and take 3 times a week. He will notice anyway that the doses in the pills in relation to the recommendations is up to 1000 times more, so most likely taking a tablet 3 times a week, Monday-Wednesday-Friday, for a few weeks is enough to notice significant increase. If one does not see significant increase, one should look the reason. And we'll get to that in a moment. Another, more scientific approach, if you will, is to try to find out if a measurement in the 200-350 zone is enough for his body. One may do the following: take folic acid for a few weeks, 3-4 or even 6, and after this time to measure homocysteine. Homocysteine is a blood test that can be done when there is lack of folic acid or B12. So, taking folic acid, we ensure that it is not deficient in folic acid and then measure homocysteine. If we see that homocysteine is low then it means that B12 is not sufficient and must take B12 supplements. Of course, anyone could ask me why do we have to do all these? The good thing is that we will have an extra piece of information, homocysteine, which is important. If the homocysteine test is below 15, the labs consider it normal, although the truth is that optimally it should be below 10. That is, answers between 10-15, although they are acceptable, they certainly are not ideal. After taking B12 dietary supplements we should examine if B12 increases. If it increases, it means that absorption is okay. If it doesn't, then one should definitely try to find why B12 isn't increased. In this case we refer to dietary supplements taken orally. Not injections. In this case we are specific about oral intake of supplementation. So someone gets B12 tablets, B12 doesn't go up, they have to go through an investigation with the help of a doctor. The specialist that will help is a gastroenterologist because the 2 more common causes of poor absorption of vitamin B12 well require gastroscopy. These are atrophic gastritis and pernicious anemia. The first is relatively common, the second is less common. Both can be diagnosed with gastroscopy, so we have to start with this examination. For the 3rd most common cause, which is inflammatory bowel disease, ie Crohn's disease and ulcerative colitis and another intestinal condition called celiac disease, there is a little more difficult to diagnose for inflammatory bowel disease, ie Crohn's disease and ulcerative colitis, a colonoscopy is usually sufficient. But we have to be aware that lesions don't always apear in colonoscopy. If the disease is in remittion we may see no lesion. Celiac disease is another diagnostic procedure, usually done with the help of a gastroenterologist again. Beyond that, there are other causes that are less common, such as a disorder in intestinal flora, immune disorders of immunity such as Lupus or Graves' disease. These are autoimmune diseases which fortunately are not very common. A very common cause is a decrease in the pH of the stomach from drugs. At least half of the cases that have low B12 are seen in people who take long-term stomach medications that reduce stomach acid. Like losec, nexium, controloc, pariet, formerly zantac and so on. Finally, some diabetes medications also reduce the absorption of B12 such as metformin sold under the brand name glucophage, glucoplus etc. Of course, we only refer to people that eat animal products because people who do not eat animal products, those who are vegan, have to take B12 supplements because otherwise it is impossible to meet their needs. So these are for the levels of B12 and what are the normal levels in the blood and how we can investigate them. Thank you very much. Good morning.