Vitamin B12 is found naturally only in animal foods: shellfish, liver, fish, meat, dairy and eggs. Plant foods do not naturally contain it, so vegans rely on fortified foods such as nutritional yeast and breakfast cereals, or supplements. The Daily Value (DV) for adults and children 4 and older is 2.4 micrograms (mcg), and the FDA considers a food providing 20% DV or more per serving a high source. The amounts below come from the NIH Office of Dietary Supplements (ODS) vitamin B12 fact sheet, which uses USDA FoodData Central values.
How much vitamin B12 you need
The NIH lists these Recommended Dietary Allowances (RDAs), in mcg per day:
- Birth to 6 months: 0.4 mcg (Adequate Intake)
- 7-12 months: 0.5 mcg (Adequate Intake)
- 1-3 years: 0.9 mcg
- 4-8 years: 1.2 mcg
- 9-13 years: 1.8 mcg
- 14 years and older: 2.4 mcg
- Pregnancy: 2.6 mcg; breastfeeding: 2.8 mcg
The foods, ranked by B12 per serving
1. Beef liver
70.7 mcg per 3 ounces (cooked, pan fried), 2,944% DV. Liver is by far the richest common source. Most people do not eat it often, and they do not need to: a small amount covers weeks of the RDA, and the body stores B12.
2. Clams
17 mcg per 3 ounces (cooked, without shells), 708% DV. Clams are the top seafood source on the NIH list and show up in chowders and pasta dishes at Florida seafood spots.
3. Oysters
14.9 mcg per 3 ounces (eastern, wild, cooked), 621% DV. Note that this figure is for cooked oysters.
4. Fortified nutritional yeast
8.3 to 24 mcg per about 1/4 cup, 346% to 1,000% DV, depending on brand. This is the key plant-based option. Not every nutritional yeast is fortified, so check the label for vitamin B12. The NIH notes that fortified nutritional yeasts and fortified cereals have high bioavailability, meaning the body absorbs the added B12 well.
5. Salmon
2.6 mcg per 3 ounces (Atlantic, cooked), 108% DV. One serving covers more than a full day's DV.
6. Canned light tuna
2.5 mcg per 3 ounces (canned in water), 104% DV. An easy, shelf-stable option for lunches and a cooler bag.
7. Ground beef
2.4 mcg per 3 ounces (85% lean, pan browned), 100% DV. A typical burger patty covers the adult daily amount.
8. Milk
1.3 mcg per cup (2% milk), 54% DV. Dairy is an important source for vegetarians who eat it.
9. Plain yogurt
1.0 mcg per 6-ounce container (plain, fat free), 43% DV.
10. Fortified breakfast cereal
0.6 mcg per serving for a cereal fortified with 25% of the DV, 25% DV. Fortification levels vary widely by product, so read the Nutrition Facts label. The FDA does not require labels to list B12 unless it has been added.
11. Cheddar cheese and eggs
Cheddar: 0.5 mcg per 1 1/2 ounces, 19% DV. Egg: 0.5 mcg per large cooked egg, 19% DV. Neither is a high source alone, but they add up over a day.
12. Turkey breast
0.3 mcg per 3 ounces (roasted), 14% DV. Poultry has less B12 than beef or fish but still contributes.
Foods that are not B12 sources
The NIH table lists 0.0 mcg for a banana, a slice of whole wheat bread, strawberries, boiled kidney beans and boiled spinach, and only 0.1 mcg (3% DV) for 1/2 cup of tempeh. These are healthy foods, but they will not meet B12 needs. That is why people who eat no animal foods need fortified foods or a supplement.
Simple ways to reach 2.4 mcg a day
Using the NIH per-serving numbers, it does not take much food to reach the adult RDA of 2.4 mcg:
- Breakfast combo: 1 cup of 2% milk (1.3 mcg) + 1 large egg (0.5 mcg) + a serving of cereal fortified at 25% DV (0.6 mcg) = 2.4 mcg.
- One fish meal: 3 ounces of canned light tuna (2.5 mcg) or Atlantic salmon (2.6 mcg) covers the day on its own.
- Vegetarian day: 1 cup of milk (1.3 mcg) + a 6-ounce plain yogurt (1.0 mcg) + 1 1/2 ounces of cheddar (0.5 mcg) = 2.8 mcg.
- Vegan day: about 1/4 cup of fortified nutritional yeast provides 8.3 to 24 mcg depending on the brand, or a supplement as advised by your doctor.
These are examples, not a prescription. Needs are higher in pregnancy (2.6 mcg) and breastfeeding (2.8 mcg), and people who absorb B12 poorly may need more than food can provide.
Vegans and vegetarians
The NIH says people who eat little or no animal foods might not get enough B12, and that fortified foods such as fortified nutritional yeast, plus B12 supplements, can substantially reduce the risk of deficiency. It also warns that exclusively breastfed infants of mothers who eat no animal products can develop deficiency, sometimes very early in life. If you are vegan and pregnant or breastfeeding, talk to your doctor about B12. Our page on B12 for vegans covers testing and options.
Who can be low even with a good diet
Food is not the only factor. The body has to absorb B12, and some people cannot absorb it well from food. The NIH lists these groups:
- Older adults. The NIH says B12 deficiency affects between 3% and 43% of older adults, depending on how it is defined, and advises that people over 50 get most of their B12 from fortified foods or supplements, which are easier to absorb.
- People with pernicious anemia or atrophic gastritis, which reduce the stomach acid and intrinsic factor needed for absorption.
- People who have had stomach or intestinal surgery, including some weight-loss surgeries.
- People with celiac disease or Crohn's disease.
- Long-term users of metformin or acid-reducing medicines such as proton pump inhibitors. The NIH suggests people taking these regularly discuss their B12 status with their health care provider.
Signs of low B12 and when to get tested
The NIH lists tiredness or weakness, pale skin, heart palpitations, loss of appetite, numb or tingly hands and feet, balance problems, confusion, poor memory and a sore mouth or tongue among the signs of deficiency. Because the body stores a large reserve, symptoms can take years to appear, and many of these symptoms have other causes. A blood test is the way to know. Our vitamin B12 deficiency page explains the lab tests, which Elon Health Urgent Care can draw on site in Davenport.
B12 injections are for people whose labs confirm a deficiency or who cannot absorb B12 well, not a general energy boost. If you are comparing clinics, see our list of places for B12 injections in Davenport, FL.
Some symptoms are not a nutrition question. Call 911 or go to the ER for chest pain, trouble breathing, a racing heartbeat with fainting, or sudden stroke signs such as face drooping, arm weakness, trouble speaking or sudden confusion. This page is general information, not a substitute for a visit.
Sources
This guide is general health information, not a substitute for evaluation by a clinician.