The Truth About Vitamin B12 Supplements
10 Minutes Read

The Truth About Vitamin B12 Supplements

Vitamin B12 – a vital nutrient for our brains, nerves and red blood cells – is lacking in vegan and vegetarian diets and hard to absorb for people with stomach and digestive problems. No wonder it’s such a popular supplement! But not all B12 supplements are equal. We blow the lid on the cheaper, synthetic B12 supplements that aren’t biologically active.
Table of Contents

    The purpose and benefits of vitamin B12

    Vitamin B12, also known as cobalamin, plays a crucial role in various bodily functions. Overall, vitamin B12 is vital for maintaining energy levels, keeping the nervous system healthy, forming new red blood cells, supporting cognitive function, and promoting overall health and well-being.

    Active forms of vitamin B12 participate in metabolic processes that convert food into energy, aiding in the breakdown of fats and proteins. this is why vitamin B12 supplements are popular to give a sudden and powerful energy boost.

    Additionally, vitamin B12 supports the synthesis of DNA and RNA, which is essential for cell growth and repair. This means you cannot regenerate or maintain any part of the body without enough B12.

    In the nervous system, vitamin B12 contributes to the production of myelin, a protective sheath that surrounds nerve fibres and facilitates efficient nerve signalling. This is why a B12 deficiency can cause tingling, numbness or even more severe symptoms. This vitamin also helps maintain the integrity of the brain and spinal cord, which is a mass of nerves. A B12 deficiency also causes damage to the brain, and severe deficiency disease resembles brain damage and mental illness.

    Furthermore, vitamin B12 is involved in the formation of red blood cells in bone marrow, ensuring adequate oxygen transport throughout the body. Without enough vitamin B12, our red blood cells become abnormally large (blood cells like this are called “megaloblasts”) and they are inefficient at carrying oxygen, so this condition is called megaloblastic anaemia.

    Who needs more vitamin B12?

    People who take certain medicines are at risk of a B12 deficiency. These include

    • proton pump inhibitors (PPIs)
    • metformin
    • nitrous oxide

    An autoimmune disease called pernicious anaemia causes vitamin B12 deficiency because the body cannot absorb it.

    Vegetarians and vegans are at risk because plant-based diets contain very little vitamin B12 indeed.

    Some people don’t absorb B12 well. These include older adults, as well as people with gastrointestinal conditions including celiac disease and Crohn’s disease. People who have had weight loss surgery such as gastric bands also fall into this category.

    Pregnant and breastfeeding women may need more vitamin B12 than average and are at risk of deficiency.

    The Four forms of vitamin B12

    Cobalamin, commonly known as vitamin B12, exists in several forms, each with distinct chemical structures and physiological roles in the body. The four primary forms of cobalamin are cyanocobalamin, hydroxocobalamin, methylcobalamin, and adenosylcobalamin.

    Depending on individual needs and health considerations, different forms of vitamin B12 may be preferred for supplementation or treatment.

    Cyanocobalamin

    Best suited for: B12 fortified foods.

    Cyanocobalamin is the synthetic form of vitamin B12. It consists of a cobalt ion bonded to a cyanide molecule – yes, cyanide! Once you eat it, cyanocobalamin needs to be changed by the body. It goes through metabolic conversion in the body to produce active forms of vitamin B12, namely methylcobalamin and adenosylcobalamin.

    Pros of cyanocobalamin

    It’s commonly added to fortified foods because it’s more stable with a long shelf life, so it’s a convenient form to use in things like breakfast cereals. It’s also used in the cheapest B12 supplements because it’s economical to make.

    Cons of cyanocobalamin

    It’s artificial, and not ready for our bodies to use. Our bodies have to convert cyanocobalamin into the active forms of B12 (methylcobalamin and adenosylcobalamin) through metabolic processes, which are less efficient than other forms.

    Hydroxocobalamin

    Best suited for: Injectable B12 formulations for treating medical conditions.

    Hydroxocobalamin is a naturally occurring form of vitamin B12 found in various foods. It contains a hydroxyl group attached to the cobalt ion.

    Pros of hydroxocobalamin

    Hydroxocobalamin has a longer half-life compared to other forms, which means it stays in the body longer. It can be stored in the body for up to 45 days, making it suitable for treating people with pernicious anaemia, an autoimmune disease which means they cannot absorb vitamin B12 from food. They have a monthly injection which has to keep their body supplied until the next injection.

    Cons of hydroxocobalamin

    Our bodies have to put hydroxocobalamin from foods or injections through a series of chemical reactions to turn it into the biologically active forms of B12. Depending on genetics, some people are less efficient at these processes and this can create a metabolic bottleneck.

    Methylcobalamin

    Best suited for: Neurological health, methylation support, genetic variants affecting B12 metabolism.

    Methylcobalamin is the biologically active form of vitamin B12 found in our bodies, once they have prepared it ready to use. It contains a methyl group (-CH3) attached to the cobalt ion, preparing it for involvement in processes such as making DNA for new body cells, producing neurotransmitters, and metabolising harmful to help keep the health heart and arteries healthy. It plays a crucial role in methylation reactions within the body. It readily crosses the blood-brain barrier and participates in processes such as DNA synthesis, neurotransmitter production, and homocysteine metabolism.

    Pros of methylcobalamin

    Methylcobalamin is easily absorbed in supplement form and used by cells. It’s considered ideal for people with neurological symptoms, mood disorders, or conditions related to impaired methylation, such as certain genetic polymorphisms or methylation pathway deficiencies.

    Adenosylcobalamin

    Best suited for: Energy metabolism, mitochondrial support, fatigue management.

    Adenosylcobalamin, also known as dibencozide, is another active form of vitamin B12 involved in cellular energy metabolism. It contains an adenosine nucleotide attached to the cobalt ion and serves as a cofactor for enzymes involved in the breakdown of fatty acids and amino acids for energy production. Adenosylcobalamin primarily functions within the mitochondria, the energy-producing organelles of cells. It is the active coenzyme form of B12 involved in cellular energy production and mitochondrial function. It additionally serves as a cofactor for enzymes responsible for the breakdown of fatty acids and amino acids within mitochondria.

    Pros of adenosylcobalamin

    Adenosylcobalamin is easily used by the body and may be beneficial for people who need to support mitochondrial function and energy levels. It enhances energy metabolism, and can relieve symptoms of fatigue or low energy levels.

    Conclusion: A dirty little supplement secret?

    Most big supplement brands sell cyanocobalamin or hydroxycobalamin. There’s nothing really wrong with them, they are vitamin B12 after all.

    But the downside is that they’re not ready for your body to use. Depending on your genetics, you may have limitations on how much of them your body can activate and use. Your levels of many other nutrients is also going to stop you converting these cheaper supplements into forms of B12 that your body can use.

    It’s clear that, if you want to feel the full benefits of a high-strength vitamin B12 supplement, it needs to deliver both body-ready forms of vitamin B12.

    VitaBright provides a dual-active Vitamin B12 supplement, blending the bio-active forms adenosylcobalamin and methylcobalamin in a 50-50 mix. As we learned above, adenosylcobalamin and methylcobalamin often work together to increase adequate intake.

    Veronica Hughes
    Veronica Hughes is a writer and researcher with a lifelong passion for nutrition and healthcare. 🩺She has spearheaded a medical research charity as its CEO, and was an influential committee member of National Institute of Health and Care Excellence (NICE) to shape treatment guidelines for the NHS. She has actively contributed to the development of Care Quality Commission treatment standards for the NHS. ✒️Her publications include newspaper articles and insightful blogs covering a spectrum of health topics, ranging from diseases and nutrition to modern healthcare and ground-breaking medical research.
    Read More From Veronica Hughes >
    Medicine & Health
    National Institute of Health and Care Excellence (NICE) treatment guidelines
    Care Quality Commission treatment standards for the NHS
    Vitamin B12 FAQs

    What is vitamin B12, and why is it important?

    What are the main sources of vitamin B12?

    What are the symptoms of vitamin B12 deficiency?

    Who is at risk of vitamin B12 deficiency?

    How is vitamin B12 deficiency diagnosed?

    Can vitamin B12 deficiency be treated?

    Are there any side effects or risks associated with vitamin B12 supplementation?

    Can vitamin B12 improve energy levels or cognitive function?

    How does vitamin B12 increase energy?

    Why do vegans need vitamin B12?

    How is vitamin B12 absorbed?