Which foods are highest in vitamin B12?

3 oz of Mussel, blue, cooked gives 20.4 µg of vitamin B12. That is 850% of the Daily Value, and it is the highest of the 1000 foods on this site that has not been fortified.

This ranking is per typical portion rather than per 100 g. Lists built per 100 g end up full of dried herbs and fortified bars, which is technically correct and practically useless, because nobody sits down to 100 g of thyme. Items marked fortified rank where they do because nutrients were added during manufacture, not because the food itself is rich in them.

How to read this list

The percentages here look absurd because the daily requirement is tiny, 2.4 micrograms, and one portion of shellfish or liver carries several days of it. That is normal for B12 and it is not a warning sign. The body absorbs what it needs and lets the rest go.

There is a catch in that last sentence. Your gut takes in roughly a fixed amount of B12 from any one dose, whatever the size of the dose. Healthy adults given 2.5, 5 or 10 micrograms in one go absorbed between 1.16 and 1.39 micrograms every time, so the share getting through fell from about 51 per cent to about 15 while the amount hardly moved. A serving listed at 3,000 per cent of the daily value does not hand you thirty days of B12. It hands you roughly what a far smaller serving would.

So read the list as a yes or no rather than as a ranking. Anything on it carrying a few micrograms in a normal portion covers you. Doubling how much B12 you eat lifts the level in your blood by about 11 per cent, which is why climbing the table buys so little.

The practical reading is simple. If you eat fish, shellfish, meat, eggs or dairy with any regularity, B12 is not your problem.

Not for everyone. If you eat no animal products at all, this list is mostly closed to you, and the fortified drink sitting in the middle of it is the shape of the answer. A supplement or fortified food is the reliable route, and B12 from a supplement is absorbed about 50 per cent better than B12 bound in food.

Where a plant product carries B12 dependably, such as many breakfast cereals, plant drinks and some nutritional yeast, it was added during manufacture. That makes the label the only reliable guide, since two brands of the same product often differ.

The source behind this page, an expert fact sheet, puts it flatly: B12 is not naturally present in any plant food. That sentence is the one thing here we can no longer repeat as it stands, and the rest of this page is why.

The plant exception, and how far it goes

One seaweed is the reason.

Unsettled. Nori, the dried seaweed sold in sheets for sushi, carries B12 the body can use. Measured with methods that separate the real vitamin from its look-alikes, a sheet holds between 1.03 and 2.68 micrograms. Thirty vegetarians taking no supplements were randomised to no nori, 5 g a day or 8 g a day. At 5 g, about four sheets, intake went from 0.3 to 2.0 micrograms and every marker moved: serum B12 up 59 pmol/L against the control group, holotranscobalamin up 28.2, homocysteine down 3.7 micromol/L. Eight grams added nothing on top of five. That is a real result in real people, and it sits directly against the fact sheet sentence above.

Two things stop it becoming a plan. The first is the packet in front of you. The same brand of nori, bought twice for the same trial, held 48.4 micrograms per 100 g when it was chosen and 38.6 in the batch people actually ate, which turned a 5 g serving from 2.4 micrograms into 1.9. Nothing on the label tells you which packet you have.

Myth. Sea vegetables are not interchangeable here, and spirulina is the one sold hardest. Weighed on a mass spectrometer, spirulina came out at one part real B12 to three parts of the inactive look-alike. Wakame carries analogues too, and the researchers behind the nori trial asked that each sea vegetable be tested and recommended on its own. Hijiki holds 0.003 micrograms in a 7 g portion and a white button mushroom cap 0.002 micrograms per 20 g dry weight, which is nothing at all. Dried shiitake is the one other entry worth naming, at 0.79 to 1.12 micrograms per 20 g dry weight.

One more plant has been through the same laboratory test. Wolffia globosa, the cultivated water lentil sold as Mankai, held four real cobalamin forms and no look-alike at all. In the trial arm eating 100 g of it a day, serum B12 rose 15.4 per cent against 5.2 per cent in the control group.

Unsettled. What storage and cooking do to any of this has not been checked. The review that gathered these numbers names it as the next job, which means every figure above describes the food as it was analysed rather than as it reaches your plate.

Not for everyone. If you eat no animal products, none of this is a reason to drop a supplement. Nori is food rather than a dose. The amount shifts by a fifth between packets of one brand, nobody has measured what storage takes out, and the trial that showed it working ran in adults who ate four sheets a day and kept doing it. It says nothing about a pregnancy, an infant, someone whose gut cannot absorb B12 from food, or anyone already being treated for a low level. In all of those, the tablet or the fortified food stays, and the blood test is what settles it.

Written from the evidence cards and the data on this page, then checked back against the sources. Bioma Learn has no human medical reviewer at this time and we say so rather than invent one. Information, not medical advice. How we verify.

Full ranking →

Full guide: Vitamin B12: who actually needs to worry, and why the damage can be permanent

Data: USDA FoodData Central. % Daily Value against the FDA DV of 2.4 µg. Checked 2026-09-15.