From the Guidelines
Foods high in vitamin B12 include animal products such as liver, clams, beef, tuna, salmon, eggs, and dairy products like milk, cheese, and yogurt, as well as fortified foods like nutritional yeast, plant milks, breakfast cereals, and meat substitutes for those following a vegetarian or vegan diet. According to the study published in Nutrition Research Reviews 1, vitamin B12 is synthesized by bacteria living in the gastrointestinal tracts of animals, making animal products rich sources of this vitamin. The study also mentions that vitamin B12 is stored in relatively large quantities in the liver, highlighting the importance of liver as a dietary source.
Some of the key food sources of vitamin B12 include:
- Liver
- Clams
- Beef
- Tuna
- Salmon
- Eggs
- Dairy products like milk, cheese, and yogurt
- Fortified foods like nutritional yeast, plant milks, breakfast cereals, and meat substitutes
It's worth noting that the body absorbs B12 through a complex process requiring stomach acid and intrinsic factor, which is why some people, particularly older adults or those with certain digestive conditions, may have difficulty absorbing enough B12 from food alone, as mentioned in the example answer. In these cases, supplements or B12 injections might be necessary, as supported by the general knowledge of vitamin B12 deficiency treatment. Including a variety of these B12-rich foods in your diet regularly helps prevent deficiency and supports overall health, with adults needing approximately 2.4 micrograms of B12 daily, as mentioned in the example answer. The study published in the American Journal of Kidney Diseases 1 also lists animal foods like meat, fish, poultry, cheese, milk, eggs, and vitamin B12-fortified soy milk as sources of vitamin B12, further emphasizing the importance of these foods in preventing deficiency.
From the Research
Foods High in Vitamin B12
Foods high in vitamin B12 are primarily animal products, including:
- Dairy products
- Meat
- Fish
- Eggs As stated in the study 2, humans are dependent on these animal foods for vitamin B12, and a diet low in animal products increases the risk of vitamin B12 deficiency.
Vitamin B12 Deficiency
Vitamin B12 deficiency is common worldwide, especially in populations with low consumption of animal foods due to low socioeconomic status, ethical reasons, or lifestyle choices, such as veganism 2. The European Food Safety Authority recommends an adequate intake of 4.0 μg/d of vitamin B12 for adults, with higher requirements during pregnancy and lactation.
Health Risks Associated with Vitamin B12 Deficiency
Vitamin B12 deficiency can have significant health consequences, particularly for pregnant women, infants, and the elderly. For example, a study on Crohn's disease patients found a high prevalence of vitamin B12 insufficiency, which can lead to hyperhomocysteinemia and increased risk of atherosclerosis 3. Another study demonstrated the effectiveness of oral vitamin B12 treatment in normalizing serum vitamin B12 levels and curing clinical manifestations related to vitamin B12 deficiency in patients with gastrointestinal disorders, including Crohn's disease 4, 5.
Dietary Recommendations
While plant-based diets have been shown to confer improved health and environmental benefits, they can also increase the risk of vitamin B12 deficiency if not properly planned. As noted in the study 2, a diet rich in plant-based foods and with fewer animal source foods requires careful consideration of vitamin B12 intake. Supplementation may be necessary for individuals with restricted diets or those who are at risk of deficiency, such as patients with celiac disease or Crohn's disease 6.