What Diet Should Be Taken in B12 Deficiency?

November 17, 2025 •

3 min read

Globally, up to 40% of adults may have suboptimal vitamin B12 levels, highlighting the critical importance of understanding what diet should be taken in B12 deficiency to maintain neurological and hematological health.

Quick Summary

Optimizing intake of animal products and fortified foods effectively addresses vitamin B12 deficiency. Specific dietary strategies are crucial for maintaining healthy nerve cells and red blood cell production. Dietary changes, alongside potential supplements, are key for recovery.

Key Points

Primary Sources: Vitamin B12 is naturally present only in animal products like meat, fish, dairy, and eggs.
Vegan/Vegetarian Needs: Individuals on strict plant-based diets must rely on fortified foods (cereals, plant milks, nutritional yeast) or supplements.
Absorption Issues: Older adults and people with gastrointestinal conditions (e.g., Crohn's, pernicious anemia) often have difficulty absorbing B12 from food.
Recommended Intake: The average adult requires approximately 2.4 micrograms (mcg) of vitamin B12 daily.
Severe Deficiency Treatment: Dietary changes alone may not be enough for severe deficiencies; injections or high-dose oral supplements might be necessary.

Understanding Vitamin B12 and Its Importance

Vitamin B12, or cobalamin, is a water-soluble vitamin vital for numerous bodily functions. It plays a key role in DNA synthesis, the formation of healthy red blood cells, and the proper function of the nervous system.

The human body does not produce vitamin B12 naturally; it must be obtained from external sources. Once consumed, B12 binds with a protein called intrinsic factor in the stomach to be absorbed in the small intestine. A deficiency can develop over several years because the liver can store a significant amount of the vitamin (up to 2-5 mg).

Causes of B12 Deficiency

While inadequate dietary intake is a major cause, especially in vegetarians and vegans, impaired absorption is also common, particularly in older adults. Conditions like pernicious anemia (an autoimmune condition where the body cannot produce intrinsic factor), atrophic gastritis, Crohn’s disease, and certain medications (like metformin and proton pump inhibitors) can hinder B12 absorption.

Dietary Strategies for Addressing B12 Deficiency

To correct a vitamin B12 deficiency through diet, individuals must focus on foods where B12 is naturally present or foods that have been fortified.

1. Animal Products

Vitamin B12 is naturally found in animal-based foods. For non-vegetarians, incorporating these foods regularly is the most effective dietary strategy.

Organ Meats: Beef liver is one of the richest sources, containing extremely high amounts per serving.
Shellfish: Clams, oysters, and mussels are excellent sources of cobalamin.
Fish: Fatty fish like salmon, trout, and tuna provide substantial amounts.
Meat: Beef, poultry, and pork are good contributors.
Dairy Products: Milk, cheese, and yogurt contain B12, which is considered to have higher bioavailability than B12 from meat.
Eggs: The yolk contains a good amount of B12.

2. Fortified Foods (For Vegetarians and Vegans)

For those following plant-based diets, natural sources are absent, making fortified products essential to meet the recommended daily intake of 2.4 micrograms (mcg) for adults.

Fortified Breakfast Cereals: Many cereals are heavily fortified; checking the nutrition label is crucial as levels vary.
Nutritional Yeast: Specifically fortified nutritional yeast can be a very rich source.
Plant-Based Milks: Fortified soy, almond, and oat milks are common sources.
Meat Alternatives: Some plant-based meat substitutes and tofu products are also fortified.

Comparison Table: Top B12 Food Sources

The following table highlights common food sources and their approximate B12 content to help guide dietary choices. Values are approximate and can vary by brand and preparation.


Food (Serving Size)	Approximate B12 Content (mcg)	Percent Daily Value (DV)	Dietary Type
Beef Liver (3 oz, cooked)	70.7	2944%	Animal
Clams (3 oz, cooked)	17.0	708%	Animal
Fortified Cereal (1 serving)	1.5 - 6.0	63% - 250%	Fortified
Salmon (3 oz, cooked)	4.9	204%	Animal
Trout (3 oz, cooked)	5.4	225%	Animal
Milk (1 cup, low-fat)	1.2	50%	Animal (Dairy)
Egg (1 large, cooked)	0.6	25%	Animal
Fortified Soy Milk (1 cup)	0.6 - 2.0	25% - 83%	Fortified (Vegan)

Sample Meal Plan for Boosting B12

Breakfast

A bowl of fortified breakfast cereal with fortified almond or soy milk.
Scrambled eggs with a side of turkey sausage.

Lunch

Tuna salad sandwich on whole wheat bread.
Lentil soup (note: lentils do not contain B12, but this provides a balanced meal) with a side salad sprinkled with nutritional yeast.

Dinner

Baked salmon fillet with roasted vegetables.
Beef stir-fry.

Snacks

Plain Greek yogurt.
Cottage cheese.

Conclusion

Addressing a vitamin B12 deficiency through diet requires consistent consumption of animal products or fortified foods. While mild deficiencies might be corrected with dietary adjustments and oral supplements, underlying absorption issues may necessitate injections. Consulting a healthcare provider is essential to determine the cause of the deficiency and the most appropriate course of action.

Learn more about Vitamin B12 from the National Institutes of Health.

Frequently Asked Questions

The best foods are animal-based, including beef liver, clams, fish (like salmon and trout), and dairy products such as milk and yogurt.

No, vitamin B12 is not naturally found in plant foods. Vegans and vegetarians must consume fortified foods (like certain cereals, nutritional yeast, and plant milks) or take supplements.

Correcting a deficiency can take time, sometimes several months, depending on the severity and the underlying cause. The body stores B12 in the liver, which can take years to deplete.

Yes, lacto-ovo vegetarians can often get enough B12 from milk, cheese, and eggs, but they should monitor their intake and consider fortified foods to ensure adequate levels.

The recommended daily amount of vitamin B12 for adults is 2.4 micrograms (mcg), according to the National Institutes of Health.

Symptoms can be physical (fatigue, paleness, shortness of breath) and neurological (numbness, tingling, memory problems, difficulty walking), and can worsen if untreated.

Yes, as the ability to absorb B12 from food decreases with age, adults over 50 are often advised to consume fortified foods or take supplements, even if they eat animal products.