How much vitamin B12 is in mango seeds?

November 23, 2025 •

4 min read

According to scientific studies, vitamin B12 is exclusively produced by certain bacteria and archaea, not by plants. In this article, the scientific evidence regarding how much vitamin B12 is in mango seeds is explored, challenging misleading online claims, and providing clarity on truly reliable dietary sources for this essential nutrient.

Quick Summary

This article examines the claim that mango seeds contain significant vitamin B12, debunking this popular misconception with scientific data. It clarifies that true, usable vitamin B12 is not naturally available in plant sources like mangoes. Readers will learn why certain claims arise and discover authentic, fortified alternatives crucial for those on vegetarian and vegan diets.

Key Points

Mango seeds are not a reliable source of vitamin B12: Scientific consensus confirms that plants do not naturally produce B12; any claims of its presence are likely inaccurate or based on microbial contamination.
Older studies on B12 in mango seeds are questionable: Early research reporting high B12 levels in mango seed kernel likely measured inactive analogues (pseudovitamin B12) or was compromised by methodological issues.
Inactive B12 analogues can interfere with absorption: Some compounds in plant products mimic B12 but are inactive and can prevent the body from absorbing real B12, potentially masking a deficiency.
Fortified foods and supplements are the safest vegan B12 sources: To prevent deficiency, vegans and vegetarians should rely on fortified nutritional yeast, plant milks, cereals, or B12 supplements.
Mango seeds offer other health benefits: While not a B12 source, mango seeds contain beneficial antioxidants, protein, and minerals, though these benefits typically come from processed extracts.
B12 synthesis occurs in bacteria and archaea: The natural production of vitamin B12 is limited to certain microorganisms, which are consumed by animals or used to fortify foods for human consumption.

The Scientific Truth About Vitamin B12 and Plant Sources

Vitamin B12, or cobalamin, is a vital water-soluble vitamin necessary for red blood cell formation, nerve function, and DNA synthesis. For years, rumors have circulated online, suggesting that certain plant foods might contain this nutrient. However, the scientific consensus is clear: plants do not produce vitamin B12. This nutrient is synthesized exclusively by microorganisms such as bacteria and archaea. Any presence of B12 in plant products is typically attributed to microbial contamination, fermentation, or symbiotic bacterial relationships, and is rarely in a bioavailable, reliable form.

The Claim: How Much Vitamin B12 is in Mango Seeds?

Some older studies and various unverified sources claim that mango seed kernels contain trace amounts of vitamin B12. For example, a 2010 study cited a value of 0.12 mg of vitamin B12 per 100g of mango seed kernel. This value is astronomically high—120 micrograms—far exceeding the daily adult requirement of 2.4 micrograms. The discrepancy and lack of confirmation in contemporary research cast significant doubt on this finding. It is highly likely that these older studies either measured inactive B12 analogues (pseudovitamin B12), encountered bacterial contamination, or had methodological flaws. The vegan society and other authoritative nutritional bodies have consistently stated that relying on fermented plant sources or algae for B12 is unreliable. A recent 2025 analysis of a mango seed extract even found zero vitamin B12.

Why Mango Seeds Are Not a Reliable B12 Source

Several factors contribute to the unreliability of mango seeds as a source of vitamin B12:

Potential for Inactive Analogues: Many plant-based products, including certain types of seaweed and fermented foods, contain compounds that are structurally similar to B12 but are not biologically active in humans. These “pseudovitamins” can interfere with true B12 absorption, masking a deficiency.
Inconsistent Data: The reported nutritional content of mango seeds varies significantly depending on the variety, growing conditions, and processing methods. This inconsistency makes it impossible to depend on them as a consistent source of any nutrient, let alone one as sensitive as B12.
Risk of Contamination: The presence of B12 in some fermented or unhygienically prepared plant products is likely due to bacterial contamination. Relying on this is unsafe and could expose individuals to harmful bacteria rather than providing a stable nutrient supply.
Lack of Fortification: Unlike fortified foods, which have B12 added in a stable, measurable dose, the occurrence of any B12 in mango seeds is not the result of a controlled, reliable process. This random and unpredictable nature makes it nutritionally insignificant.

Comparison Table: B12 Sources

To put the claims about mango seeds into perspective, here is a comparison of B12 levels in various sources:


Source	Vitamin B12 Content (per 100g)	Reliability	Bioavailability
Mango Seed Kernel	Reported: 0.12 mg (120 mcg)	Unreliable	Highly questionable (risk of inactive analogues)
Nutritional Yeast (fortified)	Varies; approx. 2.4 mcg per tbsp	Very Reliable	High
Fortified Cereal	Varies by brand; approx. 0.6 mcg per serving	Reliable	High
Beef Liver (cooked)	~70 mcg	Very Reliable	High
Milk (cow's)	~0.35 mcg	Reliable	Good
Nori (dried purple laver)	Varies; can contain some active B12	Somewhat Reliable	Variable, depends on processing
Shiitake Mushrooms (dried)	Variable, lower concentrations	Somewhat Reliable	Low, may require larger quantities

Other Nutritional Benefits of Mango Seeds

While mango seeds are not a viable source of vitamin B12, they do possess other nutritional attributes that have been studied. The seeds contain a good amount of protein, crude fat, carbohydrates, and minerals such as potassium and magnesium. They are also rich in antioxidants, including phenolic compounds like gallic and ellagic acid, which are known for their anti-inflammatory, antimicrobial, and potential antidiabetic properties. Mango seed extracts have been explored for various applications, from food additives to cosmetics. However, these uses typically involve processed extracts rather than direct consumption.

Conclusion: Stick to Proven B12 Sources

The notion that mango seeds are a rich source of vitamin B12 is a nutritional myth, likely born from flawed older studies or misconceptions. Reliable evidence from modern nutritional science and health organizations confirms that fruits and vegetables do not naturally contain significant, usable amounts of B12. For those following a vegan or vegetarian diet, or for older adults who may have trouble absorbing B12, relying on fortified foods like cereals, plant-based milks, and nutritional yeast, or taking a B12 supplement, remains the only safe and effective strategy to prevent deficiency. While mango seeds have other documented health benefits, they should not be viewed as a solution for meeting your daily vitamin B12 requirements.

Reliable Vegan and Vegetarian B12 Options

For those avoiding animal products, ensuring adequate vitamin B12 intake is essential. Supplements and fortified foods are the most dependable options:

Supplements: Vitamin B12 supplements are widely available in various forms, including tablets, capsules, and sprays. For those with absorption issues, sublingual tablets or injections may be recommended by a healthcare professional.
Fortified Nutritional Yeast: A popular vegan ingredient, fortified nutritional yeast provides a significant dose of B12 and can be sprinkled on a variety of dishes for a cheesy flavor.
Fortified Plant Milks: Many non-dairy milk alternatives, such as soy, almond, and oat milk, are fortified with vitamin B12, making them a simple addition to your diet.
Fortified Breakfast Cereals: A quick and easy way to get B12 is to choose a breakfast cereal that has been fortified. Always check the nutrition label to confirm the B12 content.

By focusing on these reliable sources, you can ensure your body receives the necessary vitamin B12 for optimal health without falling for misinformation about exotic, unproven plant sources like mango seeds.

Frequently Asked Questions

No, you cannot reliably get your daily vitamin B12 needs from eating mango seeds. Scientific evidence confirms that plants, including mangoes, do not naturally produce B12. Any claims of B12 content are likely due to contamination or inactive analogues, which are not beneficial for human health.

Pseudovitamin B12 is a compound that is chemically similar to active vitamin B12 but is biologically inactive in humans. It is often found in some plant-based and fermented foods. Consuming it can interfere with the body's absorption of true vitamin B12 and potentially mask a deficiency.

The most reliable plant-based sources of vitamin B12 are fortified foods and dietary supplements. These include fortified nutritional yeast, fortified plant milks (like soy, almond, and oat milk), and fortified breakfast cereals.

Many older studies reporting high levels of B12 in mango seeds or kernels are now considered questionable or flawed. The reported amounts are significantly higher than necessary, and modern testing often finds zero or insignificant levels, suggesting contamination or the presence of inactive forms.

While mango seed powder is used in some health products for other benefits, such as its antioxidant properties, it should not be relied upon for vitamin B12. Before consuming it, research its processing and preparation, and consult a healthcare provider, especially for medicinal purposes.

Vitamin B12 is primarily stored in animal tissues and passed on through animal products like meat, eggs, and dairy. Since vegans exclude all animal products, they must actively seek out fortified foods or supplements to ensure they get enough of this vital nutrient.

A vitamin B12 deficiency can lead to serious health problems, including megaloblastic anemia, fatigue, weakness, and neurological issues like nerve damage. Ensuring sufficient intake from reliable sources is crucial to prevent these complications.