 Some of the most common questions I get are about the dosage and type of vitamin B12. Check out the video for some answers. 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, it 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 cesarean 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. 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, 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. This is how much you should take if you're low. Note the recommendations for pregnant and 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 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 cyanophorms, 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 in 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 olcalogs, that not only can our body not use, the anilongs 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? Observation 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. Check it out, 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, specifically this brand, 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, is of special importance that we secure a regular, reliable source. And the safest, cheapest, healthiest source is B12 supplements or green light B12 fortified foods.