What are the best sources of vitamin B12 and folate?

Best Sources of Vitamin B12 and Folate

The best sources of vitamin B12 are animal-derived foods including meat (especially organ meats), milk, dairy products, eggs, fish, and shellfish, while the best sources of folate include green leafy vegetables, legumes, liver, citrus fruits, nuts, and fortified breakfast cereals. 1

Vitamin B12 Sources

Animal-Based Sources

• Meat, particularly organ meats like liver and kidney, contain the highest concentrations of vitamin B12 2, 3
• Sheep meat and chicken meat have bioavailability of 56-89% and 61-66% respectively 2
• Fish meat has approximately 42% bioavailability of vitamin B12 2
• Dairy products (milk, yogurt, cheese) are reliable sources of vitamin B12 1, 3
• Eggs contain vitamin B12, though with poorer absorption (<9%) compared to other animal foods 2

Plant-Based Sources

• Most plant foods naturally contain little to no vitamin B12 2, 4
• Dried purple laver (nori) is the most suitable natural plant source of vitamin B12 for vegetarians 4
• Fortified breakfast cereals are particularly valuable sources of vitamin B12, especially for vegans and elderly people 1, 2
• Most edible blue-green algae supplements contain pseudovitamin B12, which is inactive in humans and not suitable as vitamin B12 sources 2

Folate Sources

Natural Food Sources

• Green leafy vegetables are excellent sources of folate 1
• Citrus fruits provide significant amounts of folate 1
• Legumes (beans, lentils, peas) are rich in folate 1
• Nuts contain good amounts of folate 1
• Liver is an excellent source of folate, though it's also high in vitamin A 1

Fortified Sources

• Fortified breakfast cereals are key contributors to folate intake 1
• Fortified grain products (140 μg/100g of cereal grain products) as mandated by the FDA have helped lower population homocysteine levels 1

Special Considerations

Vitamin B12

• The bioavailability of vitamin B12 decreases significantly with increasing intake per meal, as the intrinsic factor-mediated absorption system becomes saturated at about 1.5-2.0 μg per meal 2
• Approximately 50% of dietary vitamin B12 is absorbed by healthy adults with normal gastrointestinal function 2
• Food-bound malabsorption is the most common cause of B12 deficiency in older adults, affecting up to 20% of this population due to atrophic gastritis 5, 6
• Proton pump inhibitors and other medications can further reduce B12 absorption 5, 6

Folate

• Low dietary intake is the primary cause of folate deficiency 5
• Folate and vitamin B12 have considerable functional interdependence - B12 deficiency can lead to functional folate deficiency 1
• Cooking can destroy folate in foods, so raw or lightly cooked vegetables retain more folate 1

Recommendations for Different Population Groups

General Population

• Include a variety of animal foods (meat, dairy, eggs, fish) to ensure adequate vitamin B12 intake 2, 3
• Consume plenty of green leafy vegetables, citrus fruits, legumes, and nuts for folate 1
• Fortified breakfast cereals can contribute significantly to both vitamin B12 and folate intake 1, 2

Vegetarians and Vegans

• Vegetarians and vegans should consume vitamin B12-fortified foods or supplements to prevent deficiency 7, 2
• Dried purple laver (nori) can be a natural plant source of vitamin B12 for vegetarians 4
• Plant-based diets typically provide adequate or high folate intake 7, 8

Older Adults

• Older adults should ensure adequate vitamin B12 intake through food sources and possibly supplements due to reduced absorption 5, 6
• Fortified breakfast cereals are particularly valuable sources of B vitamins for older adults 1, 6
• Natural food sources recommended for older adults include lean meat (vitamins B12 and B6), milk and dairy foods (riboflavin and vitamin B6), and green leafy vegetables, legumes and liver (folate) 1

Clinical Implications

• B vitamin deficiencies are associated with increased risk of cardiovascular disease, cognitive dysfunction, osteoporosis, depression, and anxiety 5
• Lower folate concentrations have been associated with increased coronary disease risk and fatal coronary artery disease 1
• Lower levels of vitamin B6 confer an increased risk of atherosclerotic vascular disease 1
• Deficient folate and related B vitamin status can increase the risk of diseases of aging 1