B12 rich foods
Pro Research Analysisby 
Searched over 200M research papers
Vitamin B12 Rich Foods: Sources and Bioavailability
Introduction to Vitamin B12
Vitamin B12, also known as cobalamin, is an essential micronutrient that plays a crucial role in various bodily functions, including DNA synthesis, red blood cell formation, and neurological function. Humans must obtain B12 from dietary sources, as it is synthesized exclusively by microorganisms 6. This article explores the various sources of vitamin B12, focusing on both animal and non-animal foods, and discusses their bioavailability and potential for preventing B12 deficiency.
Animal-Based Sources of Vitamin B12
Meat and Dairy Products
Animal-derived foods are the primary sources of vitamin B12. Excellent sources include meat, particularly offal such as liver and kidney, and dairy products. The concentration of B12 in these foods can vary based on factors such as the animal's diet and the specific cut of meat 6. For instance, ruminant meat and dairy products are particularly rich in B12, although processing and cooking can reduce its content 6.
Fish, Eggs, and Shellfish
Fish, eggs, and shellfish are also significant sources of B12. The bioavailability of B12 from these sources varies, with fish and meat generally offering higher absorption rates compared to eggs, which have a lower absorption rate of less than 9% 2. The intrinsic factor-mediated absorption system in humans is estimated to be saturated at about 1.5–2.0 µg per meal, which affects the bioavailability of B12 from these foods 2.
Plant-Based Sources of Vitamin B12
Seaweeds and Algae
Certain types of seaweeds, such as dried purple laver (nori), contain substantial amounts of vitamin B12 and are considered suitable for vegetarians 7. However, most edible blue-green algae (cyanobacteria) contain pseudovitamin B12, which is inactive in humans and therefore not a reliable source of the vitamin 24.
Mushrooms
Mushrooms, particularly shiitake and white button mushrooms, have been identified as containing considerable amounts of B12. The B12 content in these mushrooms can vary, but they offer a viable non-animal source of the vitamin 1.
Fermented Foods
Fermented foods, such as tempeh, tofu, and certain fermented vegetables and fruits, can also be significant sources of B12. The fermentation process can enhance the B12 content in these foods, making them a feasible alternative for those on plant-based diets 39. The bioavailability and stability of B12 in these foods are important factors that require further research 3.
Fortified Foods and Supplements
Fortified Breakfast Cereals
For vegans and the elderly, fortified breakfast cereals are a particularly valuable source of vitamin B12. These cereals are often enriched with crystalline B12, which has high bioavailability and can help meet daily intake requirements 2.
B12-Enriched Vegetables
Efforts are being made to produce B12-enriched vegetables through biofortification processes. These methods involve using specific microorganisms during the fermentation process to increase the B12 content in plant-based foods 9.
Conclusion
Vitamin B12 is an essential nutrient that must be obtained from dietary sources. While animal-based foods such as meat, dairy, fish, and eggs are the primary sources, certain plant-based foods like seaweeds, mushrooms, and fermented products also offer viable alternatives. Fortified foods and supplements provide additional options, particularly for those on plant-based diets or with increased B12 requirements. Ensuring adequate intake of bioavailable B12 is crucial for preventing deficiency and maintaining overall health.
Sources and full results
Most relevant research papers on this topic
Vitamin B12 sources in non-animal foods: a systematic review
A varied diet containing non-animal B12 food sources can potentially meet daily recommendations for B12, reducing deficiency concerns for vegetarians and vegans.
Systematic ReviewVitamin B12 Sources and Bioavailability
Vitamin B12 bioavailability decreases with increasing intake, making animal foods, meat, milk, egg, fish, and shellfish the main sources.
Highly CitedFermented vegetables and fruits as vitamin B12 sources: An overview
Fermented vegetables and fruits can provide the necessary daily amount of vitamin B12 for human health and maintenance, making them a feasible alternative for plant-based diets.
Biologically active vitamin B12 compounds in foods for preventing deficiency among vegetarians and elderly subjects.
Identifying plant-source foods with high bioactive vitamin B12 levels and preparing crystalline vitamin B12-fortified foods can help prevent deficiency in high-risk populations like vegetarians and elderly individuals.
Highly CitedVitamin B12 Intake From Animal Foods, Biomarkers, and Health Aspects
A diet high in plant-based foods and low in animal products increases the risk of vitamin B12 deficiency, especially in populations with low consumption of animal products.
Highly CitedVitamin B12 in meat and dairy products.
Ruminant foods, particularly offal, are excellent sources of vitamin B12, with processing and preparation affecting its concentration.
Highly CitedVitamin B12-Containing Plant Food Sources for Vegetarians
Dried purple laver (nori) is the most suitable Vitamin B12 source for vegetarians, providing iron and n-3 polyunsaturated fatty acids, while also providing other nutrients.
Very Rigorous JournalHighly CitedVitamin B12 levels in children and adolescents on plant-based diets: a systematic review and meta-analysis.
Children and adolescents on plant-based diets, especially vegan and macrobiotic diets, may be at risk of developing vitamin B12 deficiency.
Meta-AnalysisFermented foods and beverages: a potential in situ vitamin B12 biofortification – a literature review
In situ fermentation of plant-based foods shows potential for vitamin B12 biofortification, with propionic and lactic bacteria being used.
Literature ReviewVitamin B12 in Foods, Food Supplements, and Medicines—A Review of Its Role and Properties with a Focus on Its Stability
Vitamin B12 stability in foods, supplements, and medicines depends on environmental factors, manufacturing process, and storage, with stabilization approaches ranging from minimal destabilization to innovative technological processes.
Literature Review