Andreas Moritz on Vitamin B12 – Digestion, Absorption, and Herbivores

This article is based on a video by Andreas Moritz, called Debunking Vitamin B12, which I found interesting and reasonably informative, so I thought, I want to know more. I was particularly interested in vitamin B-12 for my own health reasons, since finding my energy better after cutting back on meat, fish and high-fat dairy in my diet.

Vitamin B12, also known as cyanocobalamin, is required for every function in the body, and every single cell needs it to work. A deficiency can cause anaemia, brain and nervous system disorders, and severe gastro-intestinal problems.

The main theme of the video is that we are deficient in B12, not due to not eating enough B12 foods, but due to not absorbing enough B12 from our foods.

He is in favour of vegetarianism generally, but not as staunch as some, a bit more balanced than most, which I liked.

What’s his own diet like, I wondered? So I looked it up and couldn’t find anything. And unfortunately he has died, apparently under mysterious circumstances, as he seemed to be fit, healthy and strong beforehand, but he was researching areas sensitive to Big Pharma/Food industry – that’s the impression I got.

Anyway, he talks about intrinsic factor in the stomach. In order to digest, absorb, assimilate B12, we need intrinsic factor in larger quantity than we generally have it.

What is intrinsic factor, I wondered? So I looked it up.

Intrinsic factor

Intrinsic factor is produced by the cells lining the stomach and combines with vitamin B12, and so it is necessary for absorption of vitamin B12 later on in the small intestine. It is a glycoprotein. (The “glyco” just means there is a carbohydrate group attached to the protein part.)

The stomach acids release vitamin B12 from food during the digestion process, but vitamin B12 is sensitive to acids and so it needs to be protected. Therefore the process starts much earlier in the mouth with the salivary glands, where vitamin B12 is combined with another glycoprotein called haptocorrin, which safely transports it through the stomach, protecting it from the acids, and on in to the intestines, where there is a more alkaline environment, and it can be safely released and absorbed.

The same cells in the stomach that produce the gastric hydrochloric acid also produce the intrinsic factor (IF), which rebinds the B12 after its release from haptocorrin by digestion. So in the duodenum, a vitamin B12-IF complex is created, which then travels on through the small intestines. Interesting stuff – amazing body, eh?

Where we find it and why we need it

It is now well-known, especially among the vegan/vegetarian community, that we need to make sure we get adequate vitamin B12 in our diets. As it’s mostly found in fresh animal products, like liver, fish, meat, poultry, eggs, milk and cheese, you can’t just eat a healthy plant-based diet and hope you get enough. It an essential vitamin, and can cause irreversible and quite severe problems if there is a deficiency.

It used to be thought, however, that people could get it from non-animal sources, like spirulina, and fermented and cultured foods like tempeh, or not cleaning the soil completely off food taken from the ground. But the Vegan Society now states that fortified foods and supplementation are the only reliable sources of B12, and that eating only a raw (rather than cooked) plant-based diet offers no special protection.

What it’s good for

We need it for the brain and nervous system (so think stability of mood, memory, eyesight), energy metabolism (production of ATP, fatty acid and amino acid metabolism) and growth (blood formation, protein and tissue synthesis) – pretty important then I’d say!

The main symptoms of a deficiency, as stated, are anaemia and neurological problems, so the elderly need it to protect against brain atrophy and things like Alzheimer’s disease, and a lack of B12 can break down the myelin sheath protecting the nerves, causing multiple sclerosis and fibromyalgia.

A deficiency can also cause thickening of the arteries, due increased circulating homocysteine, a digestion byproduct that can cause damage throughout the entire body, which B12 normally acts to break down.

So a deficiency can start with unclear symptoms, like loss of energy, a sore tongue, tingling in the hands, mild confusion, but if left untreated can lead to serious problems: nerve damage (even the spinal cord can breakdown), low bone mineral density, and eyesight deterioration, plus mental health problems, depression.

So being found mostly found in animal products and dairy, that’s why vegans need to make sure they get an alternative source in their diet.

Best sources of B12


The only vegan sources are fortified cereals, milks, juices, soy and other products, and yeast-containing products like Marmite (UK name, or Vegemite in the US, and it goes under other names too, basically yeast extract – that black gooey, salty stuff you spread on your toast), but these are relatively minor amounts.

For example, Marmite contains 0.5 mcg per 100 g, but we only tend to use a teaspoon or two on our toast because it’s such strong tasting stuff, so that only contains 0.025 mcg. Whereas a cup of fortified soy milk will contain 3 mcg, which is 50% of the DV (daily value – see below).

And there is another issue here if you’re going to add fortified products to your diet, in the UK at least, the soy, almond and rice milks that contain added vitamins also contain gums (gelan gum and/or carrageenan usually), which are known to cause digestive issues – more below.


Obviously the situation is better if you are vegetarian because you can have eggs, milk, cheese and yogurt. Also whey powder, as 100 g of that is said to contain 42% DV.

And with milk and yogurt, you’re more likely to consume a whole cup of that, which contains 0.9 mcg (15% DV) for non-fat yogurt, and 1.14 mcg (19% DV) for reduced fat milk. So a bit more but still not brilliant though.

Even with eggs, unfortunately, 1 large boiled egg only contains 0.6 mcg, just 10% of the DV, although other types of eggs contain more, e.g. duck eggs contain 3.8 mcg (raw, not sure about cooked), which is 63% DV, and goose eggs, which are rather large, contain 7.3 mcg, which is 122% DV. But then I personally find duck eggs too fatty – you just can’t win, can you?

Daily allowance

The recommended amount you need varies between countries (according to sources on the Internet): the UK RDA (recommended daily amount) is 1.5 mcg/day (from the National Health Service website, so should be accurate and up-to-date).

Google (no source given, but which turned out to be the US RDA – recommended dietary amount) says: 2.4 mcg daily for ages 14 years and older, 2.6 mcg daily for pregnant females, and 2.8 mcg daily for breastfeeding females. For the over 50s, they should eat foods fortified with B12 or take a vitamin B12 supplement.

So those over 50, and pregnant and breast-feeding women, need more due to reduced absorption in older people of naturally occurring B12, and greater demands for B12 whilst pregnant and for nursing mothers.

Note that the DVs quoted above are based on 6 mcg daily (rather confusingly), rather than the US RDA of 2.4. (It’s to do with the value in the food apparently, rather than the daily amount you need). So that applies to reading the nutrition labels for fortified foods, which is why for egg, quoted above, it’s 0.6 mcg, which is 10% DV, not 25% (which would be the relative amount for the RDA of 2.4 mcg).


A Dutch study (from 2005) looked at how much oral B12 should be prescribed for patients with a confirmed deficiency of this vitamin – NB the population studied were elderly (people with what was termed a mild B12 deficiency), with an average age of 80. This was usefully pointed out by Hyla Cass M.D., in “Vitamin B12 – How much is enough?” (1)

They were given B12 (cyanocobalamin form) in a range of doses: 2.5, 100, 250, 500 and 1000 mcg daily (administered for 16 weeks).

No adverse events were reported with any dosage, but the principal result was that the 500-mcg dose was the lowest dose required for an oral dose, for patients with a confirmed deficiency of this vitamin (measured by an estimated 80% to 90% reduction in plasma methylmalonic acid).

So this study was for supplements, and the value found is quite high compared with the daily values needed, which is the amount recommended that we get from foods.

As further confirmation, a supplement from a trusted source I know of provides 1,000 mcg/capsule, which also contains 400 mcg of folate. And most supplements contain 500 mcg or 1,000 mcg (which might be the difference between the therapeutic dose and a maintenance dose).

Easier to absorb

The good thing about supplements is that in some people, the B12 is easier to absorb than that found in naturally occurring foods, where it is bound to protein. Reduction in stomach acid and digestive enzymes with increasing age, and things like inflammation of the stomach lining due to allergies, food intolerances, alcohol intake, conditions like celiac disease and Crohn’s disease, all reduce body’s ability to cleave the required nutrient from the food and to absorb it.

Full list of B12 containing foods

Here is a list of the top food sources of B12 (from

  • Shellfish – clams, oysters, whelk, crab (crab: Alaska, King cooked, Dungeness and Queen, cooked)
  • Liver – from lamb, beef, veal, moose, turkey, duck, goose, pork, chicken (pan-fried, then tinned)
  • Fish eggs, specifically of whitefish, caviar (black and red, granular), mixed fish roe (cooked, dry heat)
  • Organ meats and giblets: turkey giblets, beef kidney, pancreas (from various animals), beef brain, veal heart, chicken giblets, lamb heart, beef heart, turkey gizzards (cooked)
  • Fish and sea mammals – octopus, salmon (dried chum), trout (dried, then Rainbow trout, cooked), mackerel (Atlantic cooked, dry heat), kippered herring (Atlantic), dried whitefish, red salmon (smoked sockeye), King mackerel (cooked), herring (cooked dry heat), mackerel (salted), tuna (fresh Bluefin, cooked dry heat), cod (dried, Atlantic, salted), sardine (Pacific, canned in tomato sauce and canned in oil, with bone), trout (cooked), whale (dried Beluga meat), seal (dried), red salmon (canned), bass (striped, cooked), walleye pollock (cooked), snapper, (cooked), seatrout (cooked)…
  • Fortified breakfast cereals – high fibre Bran Flakes, Kellogg’s All bran Complete wheat flakes, Multi-Grain Cheerio’s
  • Complete Oat Bran Flakes, All Bran Buds, Special K, General Mills cereals, All Bran Original, Kellogg’s low fat granola
  • All Bran yogurt bites, Nature’s Path Optimum, Ready to eat muesli (with dried fruit and nuts)…
  • Pates/liver sausage: Braunschweiger (pork liver), liverwurst and liverwurst spread, foie de gras (goose liver, smoked)
  • Wild game: caribou (dried shoulder meat), emu (fan fillet cooked), beaver and muskrat, rabbit (roasted), deer, moose, ostrich
  • Margarine-like (vegetable oil) spreads
  • Whole dried egg, dried egg yolk, goose egg (whole, fresh, raw is highest)
  • Soy protein isolate
  • Soup (clam chowder, New England, tinned, condensed)
  • Meatless chicken, breaded fried
  • Baby foods (some)
  • Milk (dry, non-fat, with added vitamin A and without), Instant Milk (dry, non-fat, with added vitamin A and without),
  • Meat – roasted mutton, some lamb cuts, and other meats… (vitamin B12 content goes down from there)…

Not included above, there are also lower amounts in B12 in:

  • Mussels and other shellfish, haddock
  • Beef
  • Low fat yogurt
  • Fortified tofus
  • Swiss cheese, reduce fat mozzarella, parmesan, feta cheese
  • Ham
  • Duck eggs (being so much higher than chicken eggs), chicken eggs
  • Chicken meat

This is to give an idea of the top B12-containing foods, partly grouped by type of food, partly by highest to lowest, but note cooking methods also alter the amount significantly. Raw organ meats, for example, contain much more than cooked. And even dry heat versus steaming and braising makes a difference.

And I was surprised to see roast chicken has half the amount of low fat cottage cheese for example, and that low fat versions of dairy often contain more B12 than the full fat varieties. So that’s useful to know.

Fortified foods and gums

I personally have avoided the fortified milks because, as I say, they tend to contain gums which, I have read, stop your digestion. According to Dr P D’Adamo, they contain a lectin or other agglutinin (basically causing cells to stick and clump together, not least your red blood cells – eeek), and it is a metabolic inhibitor – that was for guar gum and carrageenan. Also for acacia (gum arabic): it flocculates serum or precipitates serum proteins, it contains lectin or other agglutinin, and is a metabolic inhibitor, and it increases lectin activity and binding – blimey, the whole caboodle! So you simply cannot break them down, and they can wreak havoc on your whole system by the sound of it.

Also see Dr Michael Greger’s video: “Is Carrageenan Safe?” (2)

Which is a shame, because it means I miss out on these fortified foods. And I don’t eat any other type of fortified foods either, like the cereals, because of the sugar and other additives they tend to contain, or bread and other wheat-based products they make with fortified flour, or use the fortified spreads (I only use olive oil and ghee generally on rye bread), and I don’t drink regular cow’s milk either, or the fortified drinks of any kind because of said gums and sugar, and I don’t use fake meat soy products, textured vegetable protein/mycoprotein – that and those smoke flavourings are definitely best avoided – and finally, I don’t eat baby food… hmm, I always liked the look of that stuff, maybe I should try it.

The reason I wonder if gums might stop the body breaking down other foods properly is because of what I learnt about the effect of, for example, adding milk to a smoothie or your morning tea or coffee. Milk actually stops you absorbing the antioxidants (the good stuff like polyphenols and catechins) in the tea and the coffee – same goes for chocolate – and even with fruits and berries you might have in your morning smoothie or breakfast bowl, adding milk actually stops the absorption of the good nutrients in it, as measured by blood levels of certain beneficial compounds after consuming it.

The scientific research done on this is handily summarised by Dr Michael Greger, an MD (medical doctor) who trawls the scientific literature for such useful information, and is presented in short, info-bitesize videos, making it more accessible for us.

And shockingly, it’s not just cow’s milk that does this, it’s soy milk as well – at least in tea – because unfortunately the only study they tested soy milk in was the one with tea. They didn’t test soy milk in the other (separate) studies on the chocolate/coffee and berries. So how about that then? That really surprised me, as it did Michael Greger, and no doubt the researchers as well. To find that adding even soy milk to healthy drinks/smoothies might be negating the beneficial effects of the antioxidant compounds in them. That was a real eye-opener.

I guess that’s part of the reason why dark chocolate is so much healthier than milk.

And so if the milk itself blocks absorption, I obviously wondered what the added gums in milk can do. So I’d rather just avoid them altogether, if I can.

B12 absorption – anatomy and controversy

Back to the video:

Andreas Moritz says undigested meat and protein in our guts upsets the probiotic bacteria, and that these bacteria are the principle source of vitamin B12 – didn’t know that – which is typically absorbed at the end of the small intestine in the terminal ileum.

(As an aside, I wondered whether the “terminal ileum” was the Appendix, as I had mine out when I was aged about 8 and I’ve have always been super-sensitive to foods, although not officially allergic to any). Anyway, it isn’t the appendix, because I looked it up.

Terminal ileum

The terminal ileum occurs between the large and small intestines and connects to the caecum (the first part of the large intestines) via the ileocecal valve. So it’s not quite the appendix but close, anatomically speaking, as the appendix is connected to the caecum.

Here is a 3-D picture ( showing the exact location of the terminal ileum within the abdomen, with a navigation grid to the left which, if you hover the little hand over it, highlights in green whatever part of the digestive system you want to look at. There is also a short description with each area. 

Storage of B12

The terminal ileum is where B12 gets absorbed into the bloodstream and carried to the liver. The liver stores it there until required, and it is then recycled in most cases. The recycled B12 is used for up to 6 or 7 years.

The amount we need in an entire lifetime is as much as you can fit on the end of your little finger – interesting! Very small amount.

So it’s quite difficult to get a B12 deficiency, and as already stated, it’s not so much the food we eat, as the absorption of it that is the cause of the problem. Our own gut health is the problem.

He goes on: Junk food and medications, particularly antibiotics, destroy the probiotic bacteria in our gut. Plus eating a lot of meat which, although it contains B12, cannot really be absorbed properly if the digestion is not working very well, particularly when intrinsic factor is diminished, which does happen when you eat too much protein foods, he says.

He says the misunderstandings about B12 come from how we produce our own B12. Like cows, for example, don’t have to eat meat or drink other species’ milk in order to get B12, and that it is provided from the plant foods, and they don’t have a deficiency.

And, Andreas makes the point: Humans eating natural foods will also not develop B12 deficiency.

(This is a hotly debated topic, as to whether we can produced our own B12 from the bacteria in the gut, coming down now on the side of we can’t, or some of us may do but it is not absorbable by us, but read on.)

So how do herbivores get their B12 then? I was curious and had a look:

Herbivores and B12

Ruminants, such as cows, buffalo, goats, sheep, these guys get their vitamin B12 from these bacteria which synthesise it in their voluminous four-chamber guts. Some herbivores (horses, elephants, zebras, rabbits, hares, and many rodents) have large caecums in their digestive tracts, which is between the small and large intestine, where bacterial fermentation takes place.

Primates eat eggs and insects in the soil. Gorillas (also hares, rabbits, and some rodents) eat faeces as well. And lots of animals regularly ingest soil, so they have many more sources/ways of getting B12 than us.

As an aside, there is a suggestion that all animals need supplementation of B12 in their feed, but one source says that bacteria in a horse’s digestive tract are able to produce enough B12 if there is enough cobalt in the diet. Leading to the suggestion that often our soil is depleted of these essential minerals these days.

There are various other references about bacteria and vitamin B12 production, if you are interested, online (3).

Increasing the absorption

Other vitamins are necessary for good absorption of vitamin B12 supplements. For example, it is recommended you include foods rich in vitamin B6 in your diet, as vitamin B6 is necessary for the proper absorption and storage of vitamin B12.

Foods such as spinach, poultry, brown rice, avocados, walnuts and bananas. Poultry includes: chicken, quail, turkey, duck, goose and pigeon.

Folate is also necessary for good absorption: from dark leafy greens, parsley, romaine lettuce, broccoli, asparagus, cauliflower and beets, fruit, and beans, peas and lentils.

Along with adequate intake of calcium. One study in 2000 found that patients with diabetes were able to reverse low vitamin B12 levels by increasing their calcium intake(4).

Some calcium rich foods are: collard greens, broccoli and kale; sardines and salmon; ricotta, mozzarella and cheddar cheese; low fat yogurt, Greek yogurt and skimmed milk; fortified: milks, cereals and tofu; beans, sesame seeds, dried figs, and molasses.

Importantly, stomach acid levels and pepsin (protein digesting enzyme) are key to extracting the B12 from our food. If you have low stomach acid, taking betaine hydrochloride supplements can help to cleave the B12 from the protein foods.

It is noted by Sandi Busch on (5) and Dr J E Williams (integrative medicine practitioner for 25 years), that use of antacids reduces stomach acid, and heavy drinking causes the stomach lining to become inflamed, thereby reducing the digestive enzymes. Some integrative medicine practitioners recommend cranberry juice and using spices in food, which help with the absorption of B vitamins in general, and some even say consider caffeine, as this increases stomach acid production.

Also eating smaller, regular amounts of B12-containing foods, rather than all at one meal, can increase the amount you absorb overall as well, because there is a limit to the amount that can be absorbed at any one time, due to the availability of the intrinsic factor.

Other considerations

Andreas is an advocate of vegetarianism but says B12 deficiency has nothing to do with vegetarianism, and that meat eaters are just as deficient, if not more so (which has been confirmed by studies in the literature). But vegetarians can suffer too if they take medication, for example, or have used antibiotics in the past. Apparently the probiotic bacteria population in your gut can be disturbed for many years after.

To improve digestion, he says to clean out the liver and bile ducts, to get rid of gall and hepatic stones. They inhibit the body’s ability to digest food properly. As already stated, this interferes with good bacteria population. And so putrefying food, whether vegetables or meat, will lead to diminished absorption of B12 because of lack of probiotic bacteria, he says, which is the major source of B12.

NB: I imagine that partly explains why undereating is better for you than overeating. With undereating, you have no rotting food in your gut.

He says finally, B12 absorption also depends on how much vitamin D you have available to keep your digestive system strong and vital. So exposing the whole body to the sun on a regular basis will improve the healthy bacteria populations in the gut, and lead to stronger absorption of nutrients generally. (Maybe he’s an advocate of naturism too! He lived in a warm climate no doubt… ah, his Ener-Chi Centre is in North Carolina… moderate climate then! )

Other sources of vitamin D – (some overlap with the list for vitamin B12 I notice):

  • Fatty fish and tuna
  • Mushrooms (that are grown in the light – although ones that aren’t can still have some vitamin D and can be put in the sun which will increase the levels apparently)
  • Good old fortified milks, orange juice and cereal
  • Egg yolks
  • Beef liver
  • Cod liver oil
  • Vitamin D supplements

Vitamin B12 in nature

Andreas didn’t believe we would necessarily absorb B12 that well from a supplement, because in nature, it never comes alone, always combined with other B-vitamins, other vitamins and minerals, and even more substances that allow B12 to be absorbed and utilised, so eating a balanced, healthy diet is key to absorbing this vital nutrient.

Andreas Moritz was very ill when growing up, he says from eating too many dairy products and animal proteins, and that when he stopped eating them, he got the colour back in his face, whereas before he was as white as snow. And because of his own illnesses in childhood, he dedicated his life to studying the root causes of disease.

Described as a medical intuitive and writer, he spent his adolescence studying nutrition, and by age 20 had trained as an iridologist. He then studied Ayurveda in India, followed by shiatsu and various other forms of energy medicine.

Although I didn’t manage to find details of his daily diet, he does have more general diet advice online at his Ener-Chi Centre.


1. Vitamin B12-How Much Is Enough? by Hyla Cass, M.D.

2. Dr Michael Greger (2013): Is Carrageenan Safe?

3. MIT biologists solve vitamin puzzle. MIT news.

4. Increased intake of calcium reverses vitamin B12 malabsorption induced by metformin. Diabetes Care. 2000 Sep;23(9):1227-31.

5. The Best Way to Absorb B12 by Sandi Busch.