What is vitamin B12?
Quick facts: Vitamin B12 is an essential nutrient that plays a key role in several important functions in the body, including red blood cell formation, immune support, neurological and psychological function, and your energy-yielding metabolism. Contrary to popular belief, there’s no scientific evidence to support vitamin B12 repelling mosquitoes or other insects.
Many of us realise that vitamins and minerals are important for our health and wellbeing, but it’s not always clear how we benefit from each nutrient in particular. Vitamin B12 is one of these essential nutrients often mentioned in relation to energy levels – but its true benefits go far beyond that.
In this guide, we explore what B12 is and how it supports various processes within the body. Keep reading to learn the benefits of getting enough vitamin B12 in your diet.
Because the body cannot produce B12 on its own, it must be obtained through diet or supplementation.
What does vitamin B12 do?
Vitamin B12 (cobalamin) is a water-soluble vitamin involved in a wide range of biological processes that support overall health. Since vitamin B12 isn’t produced in the body, it’s vital to make sure you get enough of it through either food or supplements.
Understanding the benefits of adequate vitamin B12 levels can help you to see why it’s so important and what can go wrong if you don’t consume enough. Below are some of the biggest benefits of regular vitamin B12 intake.
Does vitamin B12 help the immune system?
Vitamin B12 contributes to the normal function of the immune system through several different avenues, one of which is its role in cell division. When your system detects a pathogen like the flu virus, rapid cell division allows you to produce lots of white blood cells to fight the infection.
When B12 levels are too low, you might find it takes you longer to recover from minor illnesses, meaning you may feel under the weather for longer.
Does vitamin B12 give you energy?
You may have heard that vitamin B12 gives you energy, but that’s an oversimplification. In reality, vitamin B12 plays a key role in supporting your energy-yielding metabolism – the function that allows you to convert carbohydrates, fats and proteins into usable energy.
So, vitamin B12 doesn’t work like caffeine – it doesn’t “give” you energy. Instead, it helps your body to be more efficient at getting energy from the fuel you’re already giving it.
Still, the effects can be similar. Vitamin B12 is known to contribute to reducing tiredness and fatigue when you get enough of it – because it helps your body to function more efficiently.
The key phrase here is “when you get enough of it”. If you were low on B12 before, an increase in intake may provide a noticeable reduction in fatigue. But if you’re already getting enough B12 through food, taking B12 supplements is unlikely to boost your energy levels much further.
Does vitamin B12 support the blood?
Yes, vitamin B12 is involved in DNA synthesis and cell division, both of which are necessary for producing red blood cells in the bone marrow. Without enough B12, red blood cells can become abnormally large and less effective at transporting oxygen.
When your body can’t transport oxygen effectively, you can start to feel effects like shortness of breath, dizziness and weakness – as well as performing less well during physical activity.
In serious cases, low B12 levels can lead to a condition known as megaloblastic anaemia. A similar condition, pernicious anaemia, can come about when autoimmune attacks in your body prevent you from absorbing enough vitamin B12 from food. These conditions should only ever be diagnosed by a doctor.
Additionally, vitamin B12 helps to regulate levels of homocysteine in the blood. Homocysteine is an amino acid formed when proteins are broken down, and it’s usually used to make other useful substances in your body. But if levels get too high, there’s a risk of arterial damage.
Getting enough B12 helps to prevent homocysteine levels building up, as well as supporting other body processes.
Does vitamin B12 affect your mental health?
Vitamin B12 contributes to normal neurological and psychological function. It’s involved in the maintenance of the nervous system and plays a role in the production of neurotransmitters that affect mood and thinking processes.
Low levels of B12 have been associated with symptoms such as:
- Low mood
- Irritability
- Difficulty concentrating or solving problems.
However, mental health is complex and influenced by many factors, so B12 is only one part of a much broader picture.
Does vitamin B12 prevent mosquito bites?
Many people believe that vitamin B12 can prevent mosquito bites, but there’s no scientific evidence to support this claim. Studies have not shown a reliable link between B12 intake and reduced mosquito attraction.
Mosquito bites are influenced by factors such as body heat, carbon dioxide output, skin microbiota and environmental conditions. While B12 is essential for health, it shouldn’t be relied upon as a method of insect protection.
Conclusion
Vitamin B12 is an essential nutrient with wide-ranging roles in the body, particularly in blood formation, neurological function and energy metabolism. Because of this, it’s vital to get enough vitamin B12 through food or supplementation if needed to support your overall wellbeing.
FAQs
Is vitamin B and B12 the same?
Vitamin B is not a single vitamin but a group of several different vitamins, known as the B-complex group. Vitamin B12 is one specific type within this group, with the others being:
- B1 (thiamine)
- B2 (riboflavin)
- B3 (niacin)
- B5 (pantothenic acid)
- B6 (pyridoxine)
- B7 (biotin)
- B9 (folate).
Each B vitamin has distinct roles in the body, but they often work together to support energy metabolism, nervous system function and overall health.
Is folic acid the same as vitamin B12?
No, folic acid (vitamin B9) and vitamin B12 are different nutrients, although they work closely together in the body. Both are involved in red blood cell formation and DNA synthesis.
A deficiency in either can lead to similar symptoms, which is why they’re often discussed together in relation to anaemia. However, they are chemically distinct and cannot replace each other in biological processes – so it’s important to make sure you’re getting enough of both.
How to improve your vitamin B12 levels
Vitamin B12 levels can be improved through dietary intake or supplementation when necessary.
B12 is naturally found in animal-based foods such as meat, fish, eggs and dairy products. Because of this, you might struggle to get enough B12 if you’re vegetarian or vegan. To help, fortified foods and supplements may be appropriate choices.
If you think you might have low B12 levels, consult a healthcare professional for proper testing and guidance before starting supplementation.
References
National Institutes of Health Office of Dietary Supplements. (2023). Vitamin B12 fact sheet for health professionals. https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/
Harvard T.H. Chan School of Public Health. (2024). Vitamin B12. https://www.hsph.harvard.edu/nutritionsource/vitamin-b12/
World Health Organization. (2023). Micronutrients and health. https://www.who.int/
