Vitamin B12 is an essential nutrient, which means we need to get it from an external source. We actually make B12 in our gut. Well, we don't... B12 is produced by some bacteria, and we actually have some in our colon that make it, but it's too far down, it's past the point of absorption, so it doesn't help us much. Too little, too late. Okay, so where can we get it? There are three reliable sources of vitamin B12: animal products, fortified foods, and supplements. Each source has its own peculiarities, so let's look at them one by one. By the way, in the US, which of the three sources do you think people get the most B12 from? We'll look at the answer in a second. I was actually really surprised to find out. Live and learn. Starting with animal products, liver is a very concentrated source because that's where B12 is stored. One slice has several times your daily B12 requirements. Fish

and seafood have a lot too. One filet of salmon can exceed your daily needs of B12. Although because of limits on absorption, if you rely on foods to get your B12, it's often recommended you eat something with B12 a couple of times a day spaced out among your meals. We'll come back to this. Now, chicken has a lot less vitamin B12 and so does milk. When we factor in absorption, it would require four cups of regular cow milk to meet your daily requirements of B12. Eggs have a decent amount of vitamin B12 but it's not very absorbable, the bioavailability is low, it would require dozens of eggs to cover your daily needs of B12. Now, this is a bit like the protein debates: some animal sources have more B12, some have less, and for people who eat a variety of those foods it quickly adds up, but

It's worth bearing in mind these factors when you design your diet, which animal products are more effective B12 sources and which are less effective and would require you to take in large amounts of saturated fat and cholesterol to get enough B12. Eggs and liver, for example, because they're such concentrated sources of cholesterol, would require you to take in a lot of it to meet your B12, whereas fish, on the other hand, seems like a more effective B12 source overall. Also, there's this idea that B12 supplements are a vegan thing, and if you eat any animal products, you're fine. Not necessarily; it depends on which ones and how much. For vegetarians, for example, we saw milk and eggs are not the best sources, so bear that in mind and plan accordingly. Also, in animal products, B12 is bound to protein, and the acid environment in your stomach breaks them apart so you can absorb the B12, whereas the B12 in fortified foods and supplements is in free form, not bound to protein.

so the stomach acidity is not a factor for those sources. What happens with age is, stomach acidity starts to come down so it's not uncommon for people above 50 or 60 to start having some difficulty getting enough b12 from animal foods and start turning to the other two sources, fortified foods and supplements. Also, some medications like proton pump inhibitors, which reduce your stomach acid, and some medical conditions can also lower your stomach acidity so if you rely on animal products to get your b12 you want to keep an eye on those factors. Okay, second source: fortified foods. Several foods in the market have b12 added to them like breakfast cereals, plant milks, nutritional yeast, juices and some imitation meats. Most of those foods can cover your b12 needs in one serving, like a cup of fortified breakfast cereal or a cup of fortified plant milk. In fact, Americans get more vitamin b12 from breakfast cereals than any other food.

now, although those foods contain a ton of B12, there's that pesky absorption issue we touched on before. Our gut can't absorb all the B12 we take in; the receptors on our gut wall saturate pretty quick. So whether you rely on animal foods or fortified foods for B12, it may be prudent to eat a B12-containing source two or three times a day, spaced out across your meals. For fortified foods, this could be a bowl of cereal for breakfast and a cup of plant milk later on. Okay, what if you're lazy like me and you don't want to bother and you just want something quick and simple? Let's look at the third source, supplements. Every time I talk about B12, I think people already know all of this. There's no way somebody's going to cut back on animal products and not ensure another source of B12, but then I look at the stats and I pick up my chin from the floor.

some studies find over 60 percent of vegetarians are B12 deficient. 55 among children. Omnivore populations have surprisingly high rates of B12 deficiency too, so it's a stark reminder to make sure we inform people about this crucial nutrient. Our B12 stores last a couple of years, so it can take a little while for a B12 deficiency to set in, but once it does, it's no joke. Vitamin B12 is critical for red blood cell production, brain function, and cardiovascular health, and we don't want to mess with those. Common symptoms of B12 deficiency include fatigue, weakness, numbness, pale skin, memory loss, and tongue swelling. If you think you may be deficient, you can test your B12 levels; there are even test kits for sale online. By the way, it's possible to have B12 deficiency and have normal B12 levels. I know, it's a little weird. What happens is, the levels in

the blood can be normal while the levels in the tissues, in the cells, where it actually counts, are already low. A more sensitive test of your B12 status is called methylmalonic acid, and if you're investigating B12 status, talk to your doctor about it. Maybe he or she can prescribe that test. So, the take-home message here is, whatever you choose to eat, make sure you get enough B12. Okay, Mom, what type and how much? There's a pill you swallow, and there's a tablet you let dissolve slowly in your mouth. They've been tested head-to-head, aaand... it was a tie. Both work fine, so choose the one you like. There's also a liquid form, sometimes in spray. Only drawback is a shorter shelf life. And then there's B12 shots. People with special conditions like pernicious anemia may need them, but for most people, the oral route is fine. Also, most supplements contain a form of B12 called

cyanocobalamin, which works fine, but it's a little bit hard on the kidneys. So, if you have kidney issues, it might be better to get a form called methylcobalamin instead. It's written on the vial in the back, in the components, which molecule it contains, so you can double-check. Okay, how much? The recommended dietary allowance, or RDA, is 2.4 micrograms. A microgram is a million times less than a gram. Yeah, we need tiny amounts of B12. So, it goes gram, a thousand times less than that is a milligram, and a thousand times less than that is a microgram, and we need 2.4 of those. Some authors recommend getting a bit more, four to seven micrograms. That's for adults; for children, it's less depending on age. As we saw, some animal foods like a filet of salmon and some fortified

foods like a bowl of breakfast cereal can easily cover the B12 RDA, although as we also said because we can't absorb all the B12 we take in, it's safer to eat B12-containing foods more than once a day. When it comes to supplements, because of this cap on absorption, people used to recommend daily supplements with hundreds of micrograms of B12 but this study published last year showed a 50 microgram daily supplement is enough. Now, if you're already B12 deficient, if your levels are already extremely low, you may benefit from taking a higher dosage daily. Definitely talk to your doctor. Okay, what if you're lazy like me and you don't want to take it daily? They also looked at that and 2,000 micrograms once a week covered it. Now, for those of you going that doesn't make any sense, if it's

50 a day. It should be 350 a week, not 2000. First of all, settle down, goodwill hunting. And second, you're right, it is proportionally more. Because of that cap on absorption, the more we take in, the smaller the percentage we absorb. So, the 2000 is to make sure you get enough for the whole week. Okay, how much does this all cost? What's the damage? Here's a random example, basically googled it, comes down to six cents a week, not exactly gonna break the bank. On the topic of supplements, there's this idea among some people that taking supplements is not natural. If we define natural as something cavemen did, I suppose that's true, but by that definition, nothing we do is natural. The plants and the animals we eat weren't around back then, taking antibiotics when you have an infection, having surgery when something bursts inside, anesthetics, vaccines, wearing shoes, watching videos on

electronic devices. We make all of these decisions based on risk-benefit analysis, pros and cons, not on whether cavemen did it. Also, as we know, most people in our society eat factory-farmed meats, and those animals are often given B12 supplements, so most people getting B12 from animal products are basically getting it from supplements. Bottom line, all three sources are effective for getting enough B12 if you plan accordingly. Your choice. In addition to these three established sources, there are some hypothesized ones. B12 has been detected in tea leaves, tempeh, some mushrooms, several types of algae, and some organic vegetables. The plants seem to absorb the B12 from the manure. There is also duckweed, which was big news in 2019. The problem with these sources is that some have very low B12 amounts, which wouldn't really make them practical sources, but the main problem

is their human activity is uncertain. Some forms of B12 are inactive in humans, so for each source, we want to make sure not just that it contains B12 or that it's absorbed, but that it's actually functional in living, breathing humans. This is not to say you can't get B12 from those sources, but with the current evidence, they're not your safest bet; you're better off sticking with one of the established three. So there you have it, options galore. People who want to eat some animal products and don't want to take pills can get their B12 that way. People who want to avoid animal products and prefer to do something daily can do the small dose supplements or the fortified foods, and the lazy bums like me can do the weekly supplement. Plenty of options, more flexible than a double-jointed yoga instructor. For more info on supplements, check out this video where

I talk about omega-3s and healthy fats, and if you're tired of supplements, here's seven nutrition facts I wish somebody had told me about long ago. More options...

All about Vitamin B12 in 10mins

All about Vitamin B12 in 10mins