Beef liver is one of nature's richest sources of vitamin B12 (cobalamin), an essential nutrient involved in nearly all important bodily functions. A single 100g portion of this nutrient powerhouse organ meat provides 2,471% of the recommended daily intake for vitamin B12. 


Cattle grazing on a lush meadow beside the road—Beef organ supplements by One Earth Health


Article jumplinks:


What is vitamin B12?

What does vitamin B12 do?

How much B12 do you need every day?

Symptoms of B12 deficiency

What happens if you consume too much B12?

Vitamin B12 content in beef liver

How much beef liver is safe to eat every day?

What are the health benefits of beef liver?


Boost your vitamin B12 intake with One Earth Health's beef liver supplement. Made from nutrient-dense, grass-fed organs, our convenient capsules deliver a potent dose of highly bioavailable vitamin B12 in each serving. 


Understanding Vitamin B12


Vitamin B12, also called cobalamin, is a water-soluble vitamin that belongs to the B complex family. It's an exceptionally unique and complex vitamin because it contains a metal ion called cobalt. Cobalt gives the vitamin its distinct ruby-red color.


Vitamin B12 is one of the most nourishing, unique vitamins. Here’s the story behind vitamin B12:


  • Unlike other relatively simple B vitamins, vitamin B12 has an intricate chemical structure organized around a metallic cobalt atom core, making it larger and more complex.
  • In nature, B12 exists in several distinct forms with slightly different molecular structures, including cyanocobalamin, methylcobalamin, adenosylcobalamin, and hydroxocobalamin. These variants have unique properties allowing participation in different biochemical reactions.
  • Vitamin B12 is not made by plants, animals, or humans. It can only be produced by certain microorganisms such as bacteria. Plants and animals get their B12 supply indirectly by consuming these B12-producing bacteria or through bacterial activity in their guts. Humans don't have the ability to synthesize vitamin B12 because we lack the enzymes and pathways to manufacture it from scratch. The only way for humans to get vitamin B12 is by consuming foods that directly or indirectly provide the B12 made by bacteria. 
  • For proper absorption from food in the small intestine, vitamin B12 requires a special protein called intrinsic factor, produced in the stomach. Without this binding protein, B12 has difficulty being taken up by the body.


Although it has an intricate molecular structure, our bodies require only small amounts of vitamin B12 daily. Despite the tiny dosage needed, B12 is a vital coenzyme that facilitates hundreds of essential metabolic reactions.  


What Does Vitamin B12 Do?


Vitamin B12 is truly a versatile and hardworking nutrient that plays vital roles in a wide array of bodily functions and processes. Here's an overview of the many crucial jobs that B12 takes on:


  1. B12 is essential for healthy red blood cell formation. It works closely with folate (vitamin B9) to facilitate the processes that produce these oxygen-carrying cells. Without enough B12, you can develop megaloblastic anemia.
  2. Vitamin B12 helps metabolize the fats, proteins, and carbs from your diet to generate cellular energy. It keeps your body's energy production fired up and running smoothly.
  3. B12 promotes nerve cell growth and protects the insulation around nerves called the myelin sheath. It supports neurotransmitter signaling for proper brain and nervous system function too.
  4. You need B12 to create new DNA strands during cell division and development. It's critically important for rapidly dividing cells like red blood cells to prevent anemia.
  5. Adequate levels of B12 may prevent brain atrophy, memory issues, and cognitive decline as you age. This vitamin supports healthy brain cells and function.
  6. Some research indicates higher B12 levels contribute to stronger bones and reduced osteoporosis risk, especially in older adults. It plays a role in bone metabolism.
  7. B12 facilitates the breakdown of some amino acids and odd-chain fatty acids, preventing their buildup. It acts as a helper for enzymes that metabolize these compounds. Without B12, toxic levels could accumulate in the body.
  8. It regulates homocysteine levels, with high homocysteine linked to increased heart disease risk. B12 is needed to convert homocysteine into other substances to keep levels in a healthy range. Elevated homocysteine can potentially damage arteries.
  9. Vitamin B12 is involved in methylation, a process that regulates gene expression and protein function. These methylation reactions help turn genes on or off and affect how proteins are used in the body.
  10. Adequate B12 intake may reduce the risk of neural tube defects and support healthy pregnancy outcomes. This vitamin is crucial for the proper neurodevelopment of the fetus. Deficiency increases the risk of birth defects such as spina bifida.


    Types of Vitamin B12


    B12 occurs in several forms, each with a different molecule attached to the central cobalt ion of the cobalamin base. These differences stem from how the molecule is synthesized and affect its absorption and use in the body.


    Some vitamin B12 types are its most bioavailable and bioactive forms, but all forms can be converted and used by the human body to some degree. Bioavailability refers to how well our bodies can absorb and utilize the nutrients from foods. 


    1. Methylcobalamin is the naturally occurring, bioactive form of B12 found in animal-based foods such as beef liver. It is already in the metabolically active form that the body needs, requiring little to no additional conversion compared to other B12 variants, which is what makes beef liver the best source of B12.
    2. Adenosylcobalamin is another naturally occurring, bioactive coenzyme form of B12. It is also found in beef liver in smaller amounts than methylcobalamin.
    3. Hydroxocobalamin: While not naturally present in foods, this synthetic form is widely used in injectable vitamin B12 treatments due to its stability and longer half-life in the body.
    4. Cyanocobalamin is a synthetic and stable form commonly used in supplements and fortified foods. It contains a cyanide molecule attached to the cobalamin base, which the body must remove before utilizing the vitamin. Cyanocobalamin is not as bioavailable and easily absorbed as methylcobalamin and adenosylcobalamin are. 
    5. Aquocobalamin is a synthetic form that can convert to either methylcobalamin or adenosylcobalamin in the body.


    With beef liver, you can feel confident that you're getting the highly bioavailable methylcobalamin and adenosylcobalamin forms of vitamin B12, packaged in nature's optimized, easy-to-absorb delivery system. 


    If you're looking to maximize your vitamin B12 intake without the strong taste of fresh liver, our beef liver capsules are an excellent choice. Our supplements are made from grass-fed beef liver, ensuring you get all the vitamin B12 goodness in a convenient, easy-to-take capsule form. 


    Invest in your health with One Earth Health's unmatched quality and transparency in beef organ supplementation.


    “I have been taking this one month ~ I truly feel better with less brain fog than I have in years! I feel more energetic and very hopeful that it will keep improving over this next month! Thank you for making such a great product!”



    Beef liver supplement bottle by One Earth Health, packed with vitamin B12 and other essential vitamins


    How Much Vitamin B12 Do You Need?


    According to the National Institutes of Health, the recommended daily intake (RDI) of vitamin B12 is:


    • Newborn to 6 months: 0.4µg
    • Infants 7–12 months: 0.5µg
    • Children 1–3 years: 0.9µg
    • Children 4–8 years: 1.2µg
    • Children 9–13 years: 1.8µg
    • Teens 14–18 years: 2.4µg
    • Adults: 2.4µg
    • Pregnant women: 2.6µg
    • Breastfeeding women: 2.8µg


    These are the minimum daily requirements to prevent deficiency. Some experts recommend higher intakes of 4–7µg per day for optimal health and prevention of age-related conditions.


    What Are the Symptoms of B12 Deficiency?


    A B12 deficiency has far-reaching consequences. If you're suffering from a B12 deficiency, you may experience the following symptoms:


    • Extreme fatigue and weakness
    • Shortness of breath and dizziness
    • Tingling or numbness in the hands and feet
    • Loss of appetite and weight loss
    • Constipation or diarrhea
    • Confusion, poor memory, and difficulty concentrating
    • Mood disturbances (depression or irritability)
    • Smooth, sore tongue or mouth ulcers
    • Vision problems


    In severe cases, vitamin B12 deficiency can lead to neurological changes and anemia. If you notice any of these symptoms, don’t ignore them. Talk to your healthcare provider about ways to up your vitamin B12 intake. 


    They’ll probably recommend adding beef liver to your weekly menu. For those who enjoy the taste of properly cooked beef liver, they’re up for a treat. If you can’t handle the taste, texture, or smell of this delicious offal meat, One Earth Health’s liver capsules offer a convenient alternative to get your fill of vitamin B12 and other essential nutrients.


    Can Too Much B12 Be Harmful?


    You don't have to worry about consuming too much vitamin B12. Unlike some other essential vitamins where overconsumption potentially causes health issues, vitamin B12 gets a free pass. Your body has an efficient way of regulating B12 absorption and flushing out any excess through urine. There have been no reported cases of vitamin B12 toxicity from oral ingestion of foods or supplements. Even mega-dose B12 supplements, which are often recommended for those with deficiencies or absorption problems, pose essentially no toxicity risk. 


    • It is very difficult to consume excessive amounts of B12 through dietary sources alone. Animal-derived foods naturally contain very high levels of B12, but the vitamin is water-soluble and any excess consumed is efficiently removed from the body through urine.
    • High-dose B12 supplements are often recommended for those with absorption issues, deficiencies, or specific medical conditions. The tolerable upper intake level (UL) for adults is extremely high—1,000 mcg (1 mg) per day from supplements or fortified foods.
    • At very high supplemental intakes above 3 mg per day, some side effects may occur such as headache, nausea, and diarrhea. These effects are rare and typically mild.


    Unless advised otherwise by a doctor, there is no need to limit consumption of highly nutritious B12 sources such as beef liver. 


    How Much Vitamin B12 Is in Beef Liver?


    Raw beef liver contains an impressive 59.3 micrograms of B12 per 100-gram serving. A single serving of beef liver provides over 2,491% of the recommended daily intake of vitamin B12. Beef liver stands out as the most concentrated dietary source of vitamin B12, with cooked liver containing even higher levels. Braised beef liver has 70.6µg while pan-frying yields a whopping 83.1µg of B12 per serving.


    The cooking process, especially dry heat methods such as pan-frying, causes the liver to lose moisture and shrink, further compacting those B12 levels into a smaller portion. With its unique role as the body's nutrient storehouse, beef liver naturally accumulates extraordinarily high levels of B12 and other fat-soluble and water-soluble vitamins.


    For a convenient way to get this nutritional powerhouse's benefits, try our premium desiccated beef liver capsules. Our supplements provide the same concentrated B12 punch as fresh liver but in an easy-to-take pill form. Invest in your health with One Earth Health's unmatched quality.


    “I’ve had great results with the products from One Earth Health and with Faisals attention to detail and his knowledge. I would recommend their products and the results your body will get. I have Chronic Lyme disease and I was in Assisted Living. Now I have a condo and I’m lifting weights.”



    Beef liver supplement bottle by One Earth Health


    Is Beef Liver the Richest Source of Vitamin B12?


    Plenty of foods are good sources of vitamin B12, but beef liver is the single most concentrated dietary source. Let's take a look at the top 10 highest sources of vitamin B12 per 100g (3-ounce) serving:


    Pan-fried beef liver


    Cooked chicken liver


    Braised beef liver


    Cooked turkey liver 


    Raw beef liver


    Grilled lean beef, steak


    Steamed mussels


    Nutritional yeast (per 1 tbsp)


    Cooked Atlantic mackerel


    Low-fat yogurt


    Steamed Alaskan king crab


    Low-fat milk



    While seafood like clams and mussels are also high in B12, they can't quite match the sheer concentration found in beef liver. And for those following a plant-based diet, fortified foods and nutritional yeasts can provide some B12, but likely not enough to meet full requirements without supplementation.


    Whether cooked or raw, beef liver outshines all other food sources. A single 3-ounce serving of beef liver provides over 3,000% of your daily B12 needs. But it's not just about quantity. The B12 found in beef liver is incredibly bioavailable, so your body can effectively absorb it. 


    All vitamins beef liver contains are in highly bioavailable forms, meaning our bodies can readily recognize and efficiently put them to use. 


    How Much Beef Liver Is Safe to Consume?


    Beef liver is a nutritional powerhouse, but should be consumed in moderation. When you consume too much or too often, it may cause adverse effects. Here’s why:



    To strike a balance and reap the benefits of liver's dense nutrient profile without going overboard, it's recommended to consume 85–170 grams (3–6 ounces) of liver per meal, 2–3 times per week. This moderate intake allows you to obtain the essential nutrients while minimizing the risk of overconsumption.


    When you adhere to recommended portion sizes and incorporate it into a nutritious and balanced diet, you can enjoy the exceptional nutritional benefits of beef liver without compromising your health.


    Health Benefits of Beef Liver


    Beef liver is densely packed with nearly all beneficial nutrients your body needs to thrive: essential vitamins, minerals, proteins, essential amino acids, healthy fats, coenzyme Q10, and others. Here’s why beef liver is so nutritious:


    1. Beef liver is packed with iron, making it an excellent dietary source for preventing iron deficiency anemia. Its high iron content boosts the production of healthy red blood cells, ensuring optimal oxygen transportation throughout the body for increased energy and vitality.
    2. With its impressive preformed vitamin A content, liver supports healthy vision and eye function. Vitamin A is essential for maintaining clear eyesight, preventing night blindness, and protecting the cornea from dryness and damage.
    3. If you're looking to support cognitive health, beef liver is a true powerhouse. Rich in choline, a vital nutrient for brain development, it aids in memory, learning, and concentration. Its omega-3 fatty acid content also improves brain function and reduces the risk of cognitive decline.
    4. Beef liver's antioxidant profile is truly impressive. Packed with nutrients such as vitamin C, vitamin E, and glutathione, it combats oxidative stress and inflammation, two major contributors to chronic diseases.
    5. Bolstering your immune system is easier with beef liver on your plate. Its high levels of zinc, iron, and vitamin A work synergistically to enhance immune function, helping your body fight off infections and illnesses more effectively.
    6. For those following a keto or low-carb lifestyle, beef liver is a true gem. Not only is it a great source of high-quality, easily digestible protein, but it also provides an abundance of healthy fats, making it a perfect addition to your diet.


    Given beef liver's remarkable nutrient density and health benefits, the smartest move you can make for your overall well-being is to start incorporating this superfood into your diet through delicious recipes. And we've got you covered—our free keto recipe book features over 80 mouthwatering dishes that showcase beef liver and other nutrient-rich organ meats. 


    Order One Earth Health’s Beef Liver Supplement


    Despite beef liver’s exceptional benefits, many people find its taste and texture unpalatable. With our grass-fed beef liver supplements, you never have to taste the meat and still enjoy the same concentrated nutritional profile.


    Sourced from ethically-raised, grass-fed cattle in New Zealand, our freeze-dried beef liver supplements are packed with vitamin B12 and other vital nutrients, without any harmful additives. For those seeking the nourishing goodness of liver without the strong flavor, our high-quality, additive-free supplements are an excellent choice.


    Never settle for mediocre supplements when you can have the best. One Earth Health’s products are a premier choice for your health.


    Beef liver supplement benefits by One Earth Health



    Vitamin B12 in Beef Liver FAQ


    What blocks B12 absorption?


    Several factors can interfere with or block proper absorption of vitamin B12 from dietary sources:


    • Lack of intrinsic factor (a stomach protein needed to bind and absorb B12)
    • Health conditions such as pernicious anemia that impair intrinsic factor production
    • Conditions such as atrophic gastritis reducing stomach acid production
    • Intestinal disorders such as Crohn's, celiac disease, or bacterial overgrowth 
    • Long-term use of acid-reducing medications 
    • Chronic alcohol overconsumption  
    • Aging
    • Surgical procedures such as gastric bypass that interfere with B12 absorption sites


    When absorption is compromised, you need to ensure adequate vitamin B12 levels with the best B12 supplementation in a bioavailable form. One Earth Health’s beef organ supplements contain grass-fed beef liver, kidney, pancreas, heart, and spleen, all of which are rich in highly bioavailable form of vitamin B12.


    How can I raise my B12 levels fast?


    If blood tests reveal a vitamin B12 deficiency, there are several methods to quickly raise low B12 levels:


    • Take high-dose B12 supplements containing more than 1000µg of methylcobalamin or cyanocobalamin
    • Get B12 injections prescribed by a doctor (hydroxocobalamin or cyanocobalamin)
    • Increase consumption of B12-rich animal foods like beef liver, clams, mussels  
    • For vegans or vegetarians, use reliable B12-fortified foods such as nutritional yeasts and non-dairy milks
    • Start taking a daily vitamin B12 supplement, especially the methylcobalamin form


    When you correct a B12 deficiency, you can prevent or reverse symptoms such as fatigue, tingling, cognitive issues, megaloblastic anemia and permanent nerve damage.


    Does avocado have B12?


    Nutrient-dense avocados provide healthy fats, fiber, folate and other vitamins, but they do not contain any vitamin B12. Vitamin B12 is not present in fruits, vegetables, grains or nuts. It is only produced by bacteria and found in meaningful, bioavailable amounts in animal-sourced foods such as meat, eggs, dairy, and B12-fortified products. Any negligible B12 present in certain plant foods is likely from bacterial contamination and not enough to meet needs.


    Do I need B12 if I eat meat?  


    Even those who regularly consume meat, poultry, eggs, and dairy products may still need additional vitamin B12 from dietary supplements or fortified foods. While these animal products are good sources of B12, several factors can impair the body's ability to absorb and utilize the vitamin B12 they provide:


    • Lack of intrinsic factor. This is a protein produced by the stomach that binds to B12 and enables its absorption in the small intestine. People suffering from pernicious anemia have limited adequate intrinsic factor production.
    • Inflammatory bowel diseases such as Crohn's or celiac disease can damage the small intestine lining and limit B12 absorption.
    • Long-term use of acid-reducing drugs such as proton pump inhibitors decreases stomach acid needed for proper B12 absorption.
    • As we get older, production of stomach acid and intrinsic factor declines, which impairs the ability to absorb vitamin B12 effectively.


    Research shows that around 14% of adults have marginal or deficient B12 status despite consuming B12-rich animal foods. This puts them at risk of developing a deficiency over time if they do not maintain levels of B12 through supplementation or fortification.


    How to increase B12 absorption?  


    To enhance and optimize the absorption of vitamin B12 from foods and dietary supplements, several strategies can help:


    • Consume B12 with a source of protein to increase stomach acid and intrinsic factor 
    • Take B12 supplements along with meals rather than on an empty stomach
    • Choose methalcobalamin and cyanocobalamin forms of vitamin B12
    • Avoid antacid medications before eating as they reduce stomach acid levels
    • Maintain adequate stomach acid production which decreases with age 
    • Treat any intestinal inflammation from conditions like Crohn's that impairs absorption
    • Limit alcohol intake

      Does desiccated liver have B12?


      Desiccated (dried and powdered) beef liver supplements are excellent sources of highly bioavailable vitamin B12. Beef liver is one of the most concentrated naturally occurring dietary sources of B12. The gentle drying process used to create desiccated liver capsules further concentrates the already potent B12 levels by weight. 


      These whole-food supplements provide vitamin B12 in its natural, protein-bound form optimized for absorption along with intrinsic factor to facilitate uptake. Compared to basic B12 pills alone, desiccated liver offers enhanced B12 bioavailability. In addition to being an ultra-dense B12 source, desiccated beef liver also supplies bioavailable forms of iron, vitamin A, folate and other nutrients found in this nutrient powerhouse organ meat.


      How quickly can B12 levels drop?


      B12 levels can decline relatively quickly if you experience inadequate or absorption issues. Even with normal absorption, B12 stores get depleted within 1–2 years of insufficient dietary B12. For vegans or vegetarians not consuming B12 fortified foods or supplements, deficiency can develop in just 6–12 months. Those with impaired absorption from conditions such as pernicious anemia can become deficient within a few months.


      Can too much B12 damage kidneys?


      There is no evidence that high doses of supplemental vitamin B12 can directly cause kidney damage or disease in people with normal kidney function. B12 is a water-soluble vitamin and any excess is efficiently removed from the body through urinary excretion.


      People with advanced kidney disease may need to avoid high-dose B12 supplements because their impaired kidney function reduces the ability to clear excess amounts from the blood. But for most healthy adults, even large doses of over 1000µg of B12 are safe.


      Should I take B12 or B complex?


      For most people looking to support healthy B12 levels, a standalone B12 supplement is better over a B complex vitamin that contains all the B vitamins. Vitamin B12 has unique absorption and storage factors compared to other water-soluble B vitamins.


      A dedicated B12 supplement ensures you get an adequate, consistent dose of this critical nutrient. Especially for vegans or those with absorption issues who need higher doses.


      A B complex can be beneficial if you want to cover your bases for the full range of essential B vitamins such as vitamin B2, vitamin B6, folate, biotin, etc. For general health, the B vitamins work synergistically.




      Bailey RL, van Wijngaarden JP. The Role of B-Vitamins in Bone Health and Disease in Older Adults. Curr Osteoporos Rep. 2015 Aug;13(4):256-61. doi: 10.1007/s11914-015-0273-0. PMID: 26017584.


      Office of Dietary Supplements - Vitamin B12. (n.d.).


      Cao, T., Huang, X., Chen, P., Huang, Z., Cheng, Z., Lu, W., Spence, J. D., Shi, H., Cheng, X., & Liu, L. (2023). Distribution and status of vitamin B12 in Chinese adults with hypertension: a comprehensive report across 14 provinces. Precision Nutrition, 2(4), e00060.


      Further Reading

      What vitamins are present in beef kidney meat?

      Vitamin A in beef heart

      Copper levels of beef liver

      Do beef organs have iron?

      Can beef organs regulate cholesterol levels?

      Is liver meat high in vitamin C?

      What are freeze-dried beef organs?

      Selenium in beef organs

      Are beef organs high in fat?

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