 I know you work hard to make the best lifestyle choices, so you can improve your health, destiny, and longevity. And there's lots of information out there on how to do just that. So where do you start? Well, we start with the facts. Welcome to the Nutrition Facts Podcast. I'm your host, Dr. Michael Greger. My job is to bring you the latest peer-reviewed nutrition and health research, and share it with you here. Today on the show, the mighty vitamin B12. Did you know B12 is an essential nutrient that your body can't make useably on its own, so you need to get it from your diet or supplements? Today we start with the best green light sources of B12. A regular reliable source of vitamin B12 is critical for anyone eating a plant-based diet, either vitamin B12 supplements or vitamin B12 fortified foods. I've talked about my B12 supplement recommendations, either 50 micrograms a day or once a week doses of 2,000 micrograms. I think that's the simplest, cheapest way, taking it once a week. That's how I'd do it. But if you don't want to take supplements, you'd have to rely on B12 fortified foods. In which case, you'd have to eat three separate servings of B12 fortified foods, each ideally sustaining at least 190% of the so-called daily value on the product's nutrition facts level. How does that make any sense? And what's the term daily value even mean? The term daily value is used to designate to both the DRV daily reference values and the RDI reference daily intakes that are based on the recommended daily allowances all to limit consumer confusion. Aren't you less confused now? Anyway, the daily value of B12 was set at 6, which has recently changed to 2.4 in 2020, making it all the more confusing. And so 190% of 2.4 is about 4.5. Plug that into the equation and you get about 1.16 absorbed from each serving, times three times a day, and poof! There's your 3.5 for the day. Okay, so how much nutritional yeast would that be, a commonly B12 fortified food source? It depends on the brand. Going alphabetically, Bob's Red Mill brand has 730% per quarter cup, so you'd only need about four times less than that to make up a serving, so around one tablespoon. So one tablespoon of this brand sprinkled on each meal and your B12 would be taken care of. Braggs says it's even more potent at 563% per tablespoon, so just a teaspoon three times a day should suffice. Dr. Ferman's brand is explicitly unfortified, so it contains zero B12, so that's an important lesson, where you can't just assume nutritional yeast has B12. So you like finding the bulk section? You have no idea what it contains, unless you actually see the package. Starting with the Frontier Co-op brand, Zero B12. Cal brand has 500% of the daily value of B12 per three rounded tablespoons, so one rounded tablespoon should suffice as one of the servings. Now brand has more, with two teaspoons of sufficing. Red Star has 333% per one and a half heaping tablespoon, so a serving would be like one tablespoon, but not only some of Red Star's nutritional yeast varieties have any B12 at all, so just remember to check the label. Finally, Trader Joe's looks like 1.5 tablespoons, could count as one serving, so it looks like Braggs is the most potent currently available. There are all sorts of other B12 fortified foods, from plant-based meats and milks to breakfast cereals and energy drinks, but are there other green light sources, meaning plant foods from which nothing bad has been added or nothing good has been taken away? What about various algae-type products like spirulina, which are advertised as natural vitamin B12 sources? Not only do they not actually contain B12, that's usable for humans, it's even worse than that. They may contain B12 analogs, look-alike molecules that can even block your absorption of real B12. I was excited to see that there was an herbal tea with B12, but so little you'd have to like quadruple bag it, if you didn't want to take a pill, which again, I think is really the best way. The easiest option would probably be leaf-side foods. I've always loved them because they center their ingredients around my daily dozen. Unfortunately, people see them citing my science and think I have some sort of financial relationship, but of course I have no financial ties to any food company, drug company, supplements, kitchen gadgets, no personal financial ties with any commercial entity whatsoever. I'm happy to voluntarily plug leaf-side. Though as their food has kept me from starving on the road on many occasions, they're freeze-dried, so they're light and easy to travel with, and I just use my hotel room coffee maker to make hot water and poof. Okay, but anyway, each of their meals has 75 micrograms of B12, so one a day and you get all your B12 without having to take a supplement, but it's only 100% green light if you specify you want the salt-free versions. They have no added salt-fat sugar versions of all their products at no extra cost, but you have to specify that when you order. In our next story, we look at the optimal vitamin B12 dosage for kids, pregnant women, and seniors. Universal improvement of B12 status appears to be a nutritional imperative with possibly profound beneficial effects, particularly at the bookends of life at old age and infancy. I've explained the rationale for my recommendations to take vitamin B12 supplements once a week, once a day, or alternately eat sufficient daily vitamin B12 fortified foods, but for those over age 65, those guidelines go out the window. The recommendations change to everyone, taking a high daily dose of 1,000 micrograms every day. Starting at age 50, everyone, meat-eaters and vegans alike, should be taking B12 supplements or eating B12 fortified foods, but over age 65, 50 a day may not do it. Even 100 a day doesn't seem sufficient. Researchers investigated three doses and found that most didn't normalize their MMA until after the 1,000 microgram dose, MMA suppression is a measure of B12 sufficiency, but they just tested 2,500 and 1,000, maybe 250 or 500 would do it. Researchers set out to find an adequate dose at that age, and it seems we need at least about 650 to 1,000 a day in most people, hence my 1,000 a day recommendation after age 65. Okay, what about the other end of the life cycle? The consequences of B12 deficiency and insufficiency can be devastating in infancy and childhood. And this is not just a problem for plant-based pregnancies. Vitamin B12 insufficiency during pregnancy is common, even in non-vegetarian populations, about a quarter of all pregnant women aren't getting enough B12, and that number rises to nearly 1 in 3 by the third trimester. But insufficiency isn't as bad as frank deficiency, which can manifest in cases like cerebral atrophy, meaning brain shrinkage in a vitamin B12-deficient infant of a vegetarian mother. Thankfully, even severe brain atrophy can be substantially reversed with B12 supplementation, but better not to become deficient in the first place. The solution proposed by a group of French pediatricians is to recommend against raising vegan kids at all, since B12 supplementation is necessary. And they're not alone, to vegan or not to vegan. In 2016, two professional organizations, the U.S. Academy of Nutrition and Dietetics, and the German Nutrition Society, issued conflicting statements. The U.S. Academy said that even strictly plant-based diets are appropriate for all stages of the life cycle, whereas the German group echoed the French group, saying, since you have to take B12, we can't recommend a vegan diet for pregnant women, lactating women, infants, children, or adolescents. To confuse the matter further, the American Academy of Pediatrics appeared to have it both ways. In one place, repeating the U.S. Academy's position while in another place is stated that vegan diets should not be recommended for children. But I think they're just saying the same thing. Everyone agrees that a non-B12 supplemented plant-based diet is a bad idea. That's part of what the U.S. Academy means by well-planned. Everyone eating plant-based, but especially pregnant and breastfeeding women, must ensure a regular, reliable source of vitamin B12, meaning B12 supplements or B12 fortified foods. But then you may be able to get the best of both worlds. That's why there are reviews with titles like this. Plant-based pregnancy is danger or panacea. Danger, if you don't take your B12, but following a plant-based diet during pregnancy may be protective against the development of preeclampsia, pre-gravid obesity, and minimize exposure to DNA-damaging agents. It may also protect our newborns from the onset of pediatric diseases, such as pediatric wheezing, diabetes, neural tube defects, oral facial clefs, and some pediatric tumors. Vegan pregnant women have a lower than average rate of caesarean section, less postpartum depression, and lower neonatal and maternal mortality, with no complications or negative outcomes that are higher than average. In addition, a lower incidence of what used to be called toxemia, a potentially dangerous pregnancy complication known as preeclampsia. Overall, plant-based diets seem to confer protection to both mothers and newborns by not only reducing the risk of several pregnancy-related issues, but decreasing the risk of childhood disease. Children following plant-based diets might have a low risk of developing obesity, obviously less exposed to drugs used in animal production, and a favorable anti-inflammatory profile of cell signaling factors. But again, everyone on a plant-based diet has to get enough B12. Pregnant breastfeeding women can just follow my 50 micrograms a day recommendation for non-pregnant adults, or 2,000 a week, though they suggest breaking up those doses into two halves to boost absorption. After infants are weaned, they can start on 5 micrograms a day. From ages 4 through 10, they can ate half the adult dose of 25 a day, and then at age 11, they can do 50 a day or 2,000 a week. You don't have to worry about taking too much. It's water-soluble, and you'll just end up with expensive pee. In our last story about vitamin B12, we've got one word for you— cyanocobalamin. Say that five times fast. I've talked about the optimal dose of vitamin B12 supplements for adults, as well as in childhood, pregnancy, and old age to prevent vitamin B12 deficiency. But what if you already have it? How much do you have to take to treat it? Your doctor might want you to get vitamin B12 injections, but oral B12, even for those who can't absorb it well, has long been considered one of medicine's best kept secrets. It's now considered well known that orally administered B12 supplements are as effective in overcoming deficiency states as intramuscular injections when you get up to taking 1,000 micrograms a day. How long do you have to take 1,000 a day for? It depends on how low your levels start out. Because B12 status in pregnancy is so critical, there's a suggestion that plant-based women get a check throughout pregnancy and to adjust supplementation as necessary. Note the recommendations for pregnant breastfeeding women are the same as everyone else over the age of 10. So if you're a teen or adult diagnosed with vitamin B12 deficiency, you'd take 1,000 micrograms a day for one to four months, depending on how low you start out, before going back to a regular maintenance dose of 50 a day or 2,000 a week, with toddlers and small children taking smaller doses. There are two main types on the market, though. Methylcobalamin, marketed as methyl B12, and cyanocobalamin, typically marketed as just vitamin B12. Methyl is more expensive, so it must be better, right? Wrong! Cyanocobalamin is the most used form due to its high stability. See, methylcobalamin is less stable than cyanocobalamin, and is particularly susceptible to photodecomposition, meaning destruction from being exposed to light. There's no advantage to using the light-sensitive forms of cobalamin, such as methyl B12, instead of the stable cyano forms, which are readily converted into the body into the type you need where you need it. The one major exception may be kidney failure, though. Methylcobalamin may be better for those with impaired kidney function. It's been speculated that oral methylcobalamin, or injected hydroxycobalamin, may also be preferable in smokers, though it has yet to be confirmed. Because methylcobalamin is less stable, you'd probably want to take much higher doses. So, for example, in those with kidney failure, you'd be taking 1,000 to 2,000 micrograms a day compared to just 50 micrograms of cyanocobalamin, and some with normal kidney function. Another reason to use the cyanocobalamin, as opposed to the more expensive kinds, is that it has a track record of safety and efficacy, whereas, for example, in one study, even up to 2,000 micrograms a day of methylcobalamin wasn't enough to correct vitamin B12 deficiency in one of three vegans they tested it on. The bottom line is that so-called coenzyme forms of B12, like methyl B12 or adenyl B12, also known as adenosyl B12, are not likely to be superior to cyanocobalamin, which is more stable. Cyanocobalamin appears to be best suited for oral supplementation, which is why I specify its use in my recommendations. Note I also recommend ideally taking it separately as a chewable sublingual or liquid supplement. Why can't you just get it as part of a multivitamin or something? Because various vitamins and minerals mixed into the same pill can destroy active B12. Forming B12 analogs, B12 locologs, that not only can our body not use, the analogs can be potentially harmful because they can inhibit the transport of what little B12 is left. That's why using multivitamins can even be counterproductive for the supplementation of vitamin B12, and this isn't just in theory. There was a tragic case of severe vitamin B12 deficiency in an infant born to a vegan mother who thought she was doing everything right, taking a multivitamin that contained B12, though it may have also just been an inadequate dose. Why chewable or sublingual? Absorption is boosted when the B12 mixes with saliva, since you secrete a B12 binding protein from your salivary glands that helps transport B12 safely through the digestive tract. Having people chew a tablet of B12 and their B12 levels go up 10 times more than just simply swallowing the exact same pill. Vegans boosted out of deficiency, chewing a B12 supplement, but nothing, and those who just swallowed it whole. Maybe they had some sort of absorption problem or something? No, because then if you tell them to start chewing it instead of swallowing it whole, their levels shoot right up as well. My latest book, How Not to Diet, I suggest a third option to B12 fortified foods and supplements, brushing twice daily with a B12 fortified toothpaste, which was put to the test in two double-blind, randomized, placebo-controlled studies. Participants were instructed to use the toothpaste two times a day for two minutes at a time, and indeed was able to correct the markers of B12 insufficiency in the blood of vegans and among the elderly. But that was on average. Unfortunately, it didn't work in every last person, which is why it's not included in my recommendations. Though, look, if you get your levels tested before and after brushing for a few months and they go up, then you can presumably stick with it. In summary, a vitamin B12 deficiency is not to be messed around with, with the potential to cause a wide range of disorders of the gut, blood, brain, and nervous system, with the ever-increasing demand for cleanliness in our food chain, which is a very good thing. It is of special importance that we secure a regular, reliable source, and the safest, cheapest, healthiest source is B12 supplements, or GreenLite B12 fortified foods. We would love it if you could share with us your stories about reinventing your health through evidence-based nutrition. Go to nutritionfacts.org slash testimonials. We may share it on our social media to help inspire others. To see any graphs, charts, graphics, images, or studies mentioned here, please go to the Nutrition Facts podcast landing page. There you'll find all the detailed information you need, links to all the sources we cite for each of these topics. For a vital, timely text on the pathogens that cause pandemics, you can order the e-book, audiobook, or the hard copy of my last book, How to Survive a Pandemic. For recipes, check out my new How Not to Diet Cookbook. It's beautifully designed with more than 100 recipes for delicious and nutritious meals. And all proceeds ever seen from the sales of all my books goes to charity. NutritionFacts.org itself is a non-profit, science-based public service, where you can sign up for free daily updates on the latest in nutrition research via bite-sized videos and articles. Everything on the website is free. There's no ads, no corporate sponsorship. It's strictly non-commercial. I'm not selling anything. I just put it up as a public service, as a labor of love, as a tribute to my grandmother, whose own life was saved with evidence-based nutrition.