Author: Kate Scott, DipNut, mBANT, rCNHC, mIFM – DNApal co-founder | Nutrition & genetics specialist | BANT registered nutritionist 

Understanding vitamin B12

Vitamin B12, also known as cobalamin, is a water-soluble vitamin that plays a number of crucial roles in the body, including the formation of your red blood cells, DNA synthesis, nerve function, and metabolising certain amino and fatty acids (you can find out more about fat vs water-soluble vitamins here).

As a B vitamin, B12 is unique because it contains the mineral cobalt within its structure, hence the name “cobalamin”. Our bodies cannot make vitamin B12, so we need to get it from dietary sources such as animal products (meat, fish, poultry, dairy) or fortified foods. The absorption of vitamin B12 from these foods depends on something called Intrinsic Factor (IF), a protein made in the gut. People with poor gut health, certain medical conditions, genetic variations or who follow a more plant-based diet may require specialised vitamin B12 supplements or injections to keep levels optimal. 

The Benefits:

Energy:

Often feeling fatigued, sluggish, or low on energy? Vitamin B12 might be the reason. This vital nutrient plays a crucial role in converting the food you eat into energy. By assisting in the formation of red blood cells and aiding in the transportation of oxygen throughout your body, vitamin B12 ensures your cells receive the energy they need to function optimally. So, if you want to kick-start your day with a burst of vitality, vitamin B12 could be your best ally.

Brain Health:

Your brain benefits significantly from vitamin B12. This vitamin plays a pivotal role in the maintenance of the nervous system and the synthesis (making) of neurotransmitters (chemical messengers like serotonin and dopamine). Vitamin B12 is linked to improved cognitive function, memory retention, and improved mood (a). If you’re seeking mental clarity and a brighter outlook (who doesn’t need that right now?), vitamin B12 could be the brain boost you’ve been searching for.

Cardiovascular Health:

Keeping your cardiovascular system in peak condition is vital for a long and healthy life. Vitamin B12 contributes to heart health by regulating homocysteine levels in the blood. Elevated homocysteine (an amino acid) levels have been associated with an increased risk of heart disease (b) and is directly linked to low levels of vitamin B12. By helping to lower these levels, vitamin B12 plays a protective role in maintaining a healthy heart.

Cellular Renewal and DNA Synthesis:

Vitamin B12 is integral to the process of DNA synthesis and cell division. This means it plays a critical role in regenerating and repairing tissues throughout your body. From supporting skin health to promoting efficient wound healing, vitamin B12 ensures that your body’s cells are renewed and regenerated, keeping you looking and feeling your best.

Vitamin B12-rich foods:

Here are some great food sources of vitamin B12:

Animal Products:

Meat: Beef, lamb, pork, and poultry.

Fish: Salmon, trout, tuna, sardines, and other fish.

Shellfish: Clams, mussels, crab, and oysters.

Organ Meats: Liver, especially from beef or lamb, is a very concentrated source of B12.

Dairy Products:

Milk and Yogurt: Cow’s milk and yoghurt can provide some B12.

Cheese: Certain types of cheese, like Swiss and mozzarella, contain B12.

Eggs: Eggs, particularly the yolk, contain a decent amount of vitamin B12.

For those following a vegan or vegetarian lifestyle, vitamin B12 supplementation is important. This nutrient is primarily found in animal products, making it challenging to obtain from plant-based sources alone. A deficiency in vitamin B12 can lead to various health issues over time, making supplementation a crucial step to maintaining overall well-being.

Fortified Foods:

Many plant-based foods are naturally low in vitamin B12, so fortified foods have become important sources for vegetarians and vegans. Common fortified foods include:

Plant-Based Milk: Almond and other non-dairy milk are often fortified with B12.

Breakfast Cereals: Some breakfast cereals are fortified with B12.

Nutritional Yeast: Often used as a cheese substitute in vegan diets, nutritional yeast is often fortified with B12.

RDA UK:

The recommended dietary allowance (RDA) for vitamin B12 in the UK is 1.5 micrograms (mcg) per day for adults. (c)

Additional factors to consider:

Stomach Acid:

Adequate stomach acid is required to release vitamin B12 from the proteins in food. Conditions that reduce stomach acid production, such as atrophic gastritis or the use of proton pump inhibitors (PPIs) or histamine H2 receptor antagonists, can affect the release of Vitamin B12 and its subsequent absorption.

Small Intestine Health:

The absorption of vitamin B12 primarily occurs in the distal part of the small intestine (ileum), which is where the secretion of Intrinsic Factor (IF) happens. Conditions that affect the health of the small intestine’s lining, such as Crohn’s disease, coeliac disease, or surgical removal of part of the intestine, can severely impair vitamin B12 absorption.

Ageing: 

As people age, the production of stomach acid and intrinsic factor may decline, potentially affecting the absorption of vitamin B12. This is one reason why vitamin B12 deficiency is more common among older adults. (d)

Medications:

Some medications can interfere with vitamin B12 absorption. Apart from PPIs and H2 blockers, certain antacids, metformin (a diabetes medication), and certain antibiotics can affect vitamin B12 absorption. If you are on any of these medications, you should consult with your doctor about taking a B12 supplement. 

Alcohol Consumption:

Chronic excessive alcohol consumption can damage the stomach lining and affect the release of vitamin B12 from food, thereby reducing its absorption.

Your genes:  

Genetics play a role in the absorption and metabolism of vitamin B12. Several genes are involved in various aspects of vitamin B12 absorption and utilisation. The gene that we focus on in our DNA reports is the FUT2 gene.

The fucosyltransferase 2 (FUT2) gene is associated with the secretion of the H antigen in the gastrointestinal tract. The H antigen is required for the binding of Helicobacter pylori bacteria, which can interfere with the production of intrinsic factor and thus impact vitamin B12 absorption. Certain variations in the FUT2 gene are associated with a decreased susceptibility to H. pylori infection, which might indirectly influence vitamin B12 absorption.

It’s important to note that while genetic factors can influence vitamin B12 absorption and metabolism, they often interact with other factors such as diet, lifestyle, and medical conditions. Genetic testing and analysis provide insights into an individual’s genetic predisposition. So order a DNApal test today to learn more about your unique needs and relieve some guesswork!

Please feel free to comment or email hello@dnapal.me for more advice.