B12 for vegan and vegetarian athletes
Any sport — endurance and team sports alike
B12 is the clearest case on this site of a nutrient a food diary can measure but not fix. It occurs naturally in animal foods and essentially nowhere else, so an athlete eating no animal products needs a fortified food or a supplement. That is mainstream dietetic guidance rather than a fringe position, and it is not something better meal planning solves.
Why this differs from the ordinary recommendation
Look at the food table below: every entry is an animal food. That is not a quirk of how the list was built — it is the entire issue, in one column.
The plant sources people are often pointed at — mushrooms, fermented foods, most algae — either carry inactive analogues or carry amounts too small and too unreliable to plan around.
Deficiency develops slowly, over months to years, because the liver holds a store. Feeling fine this month is not evidence that intake is adequate.
Figures from the American College of Sports Medicine, Academy of Nutrition and Dietetics, and Dietitians of Canada — joint position stand, Nutrition and Athletic Performance (2016). Ranges are given at the conservative end — see the note on each number above.
Where this stops being useful
If you eat no animal foods, the standard advice is a reliable fortified source or a supplement, and the dose and form are worth getting from your doctor or a dietitian rather than from a website. B12 deficiency can cause neurological damage that does not fully reverse, which is why this is the one guide here that says see someone rather than eat more of something.
Healthy Squirrel gives nutrition estimates, not medical advice.
Foods highest in vitamin b12 (per 100 g)
| Food | per 100 g | % Daily Value |
|---|---|---|
| Mollusks, clam, mixed species, cooked, moist heat | 99 mcg | 4120% |
| Lamb, variety meats and by-products, liver, raw | 90 mcg | 3752% |
| Veal, variety meats and by-products, liver, cooked, braised | 85 mcg | 3525% |
| Beef, variety meats and by-products, liver, cooked, pan-fried | 83 mcg | 3464% |
| Goose, liver, raw | 54 mcg | 2250% |
| Duck, domesticated, liver, raw | 54 mcg | 2250% |
| Mollusks, octopus, common, cooked, moist heat | 36 mcg | 1500% |
| Mollusks, oyster, Pacific, cooked, moist heat | 29 mcg | 1200% |
| Turkey, all classes, liver, cooked, simmered | 28 mcg | 1174% |
| Pork, fresh, variety meats and by-products, liver, raw | 26 mcg | 1083% |
| Liver cheese, pork | 25 mcg | 1023% |
| Mollusks, mussel, blue, cooked, moist heat | 24 mcg | 1000% |
Per 100 g from USDA FoodData Central, whole foods, highest first. In the app every amount scales to the serving you actually log.
More detail on this nutrient: foods highest in vitamin b12.
Track it without doing the arithmetic
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