Foods with vitamin B12: Where to find this energy-boosting nutrient

There's an expression that goes: "A healthy man has 1000 wishes. A sick man has only one."

And, while the wish in question is technically his health, it could be argued that our energy is an equally valuable resource. You can have everything you desire in life, but without the energy to actually enjoy it, it will prove largely futile.

Many factors contribute to how much energy we have in our everyday lives — from hydration and hormones to sleep quality. However, another underrated variable that tends to slip under the radar is vitamin B12. Sometimes referred to as the 'energy vitamin,' the essential nutrient is foundational for many key processes in the body.

But, how do you know if you're getting enough vitamin B12 — and, how do you supplement through your diet if you're falling short? Read on for everything you need to know about this energy-boosting vitamin.

What is vitamin B12?

Also known as cobalamin, vitamin B12 is a water-soluble vitamin that's naturally available in some foods.  It's one of eight B vitamins that help your body convert the food you eat into energy.

What are the other B vitamins?

The B-group makes up eight of the 13 essential vitamins [1]. Apart from vitamin B12, they include:

• Thiamin (vitamin B1) — helps the body break down foods and keeps the nervous system healthy
• Riboflavin (vitamin B2) — helps the body release energy from food and protects the skin, eyes and nervous system
• Niacin (vitamin B3) — helps to regulate the metabolism and cholesterol levels
• Pantothenic acid (vitamin B5) — helps to synthesise coenzyme A (CoA), which is vital for energy production and the synthesis of fats, carbohydrates, and proteins
• Pyridoxine (vitamin B6) — helps the body use and store energy from protein and carbs in food, and plays a role in producing haemoglobin in the blood
• Biotin (vitamin B7) — helps support your eye, skin and hair health
• Folate (vitamin B9) —  helps produce red blood cells, create and repair DNA, and enable cell growth and division. It's especially crucial during pregnancy to help prevent defects like spina bifida

As you can see, all of the B vitamins play an important role in your overall health. However, Vitamin B12, Vitamin B6 and folate are considered the most important [2]. They're the ones where if you're deficient, you'll likely notice a tangible difference in your central nervous system and cognitive function.

What role does vitamin B12 play in the body?

Vitamin B12 has many key functions in the body. These include:

Vitamin B12 supports the production of healthy red blood cells

Without adequate vitamin B12, the body produces large, immature red blood cells that die prematurely. This can lead to a type of anemia called megaloblastic anemia, which can be caused by either a vitamin B12 or folic acid deficiency. This, in turn, can lead to fatigue and weakness, as red blood cells are responsible for carrying oxygen throughout the body [3].

Vitamin B12 helps turn food into energy

Vitamin B12 plays a crucial role in the metabolic processes that convert carbohydrates, fats, and proteins into usable energy for the body's cells [4]. It acts as a cofactor for enzymes, facilitating the breakdown of food molecules into ATP (adenosine triphosphate), which is the energy currency of cells.

Vitamin B12  helps keep you mentally sharp

If you often feel like you experience brain fog, a vitamin B12 deficiency could potentially play a role. The essential nutrient supports brain and nervous system health through several key functions, such as forming the protective myelin sheath around nerve fibres, helping produce neurotransmitters that regulate mood and cognition [5]. Carrying oxygen to the brain certainly doesn't hurt, either!

Vitamin B12 helps future-proof your brain

Vitamin B12 doesn't just help you look after your brain now, but also later down the track. It can help reduce levels of homocysteine — an amino acid that is produced when proteins are broken down — in the blood. Research shows that lowering  homocysteine helps protect against brain lesions, slower processing speeds, memory and even degenerative disorders like Alzheimer's Disease [6].

Vitamin B12 supports a healthy pregnancy and birth

Alongside vitamin B9 (folic acid), B12 is an especially crucial vitamin for women when they are expecting. It plays an essential role in the development of the baby's brain and spinal cord, helping to prevent neural tube defects [7]. It also helps to safeguard against anaemia and fatigue in mums-to-be.

Vitamin B12 helps improve overall longevity

Vitamin B12 also works at a DNA level to help improve our quality (and length) of life. It's essential for DNA synthesis and stability, because it acts as a coenzyme that creates DNA components and through its role in DNA methylation  — a process that regulates gene expression [8]. It also helps protect DNA against scavenging free radicals, which can cause inflammation in the body.

What are the recommended intakes for vitamin B12?

Adults aged 19 to 64 need about 1.5 micrograms a day of vitamin B12 [9]. If you eat a varied and balanced diet, you likely won't have too much difficulty reaching this target. However, as vitamin B12 is mostly found in animal foods, vegans and vegetarians may find it more challenging than the general population.

How is vitamin B12 absorbed?

Vitamin B12 is absorbed in the terminal ileum, through a multi-step process that involves releasing it from food proteins, binding it to transport proteins, and finally, being absorbed by specialised cells [10]. This process begins in the stomach where acid and enzymes release B12 from food, which then binds to a protein called haptocorrin (or R-binder).

Older adults in particular can have difficulty absorbing Vitamin B12, as the digestive system can become less efficient over time [11]. It's typically absorbed more efficiently alongside other B vitamins, like B6 and folate [12]. That's why you'll often find it in a combined B complex vitamin format.

Can you increase your vitamin B12 levels naturally?

It's important to note that although we need vitamin B12, our bodies cannot naturally produce it. This is why we need to get it through dietary sources and supplements.

What foods are high in vitamin B12?

Wondering which foods have vitamin B12, exactly? Here's the lowdown.

Animal-based sources of vitamin B12

As B12 binds to protein, most animal products are naturally high in vitamin B12. Some examples of animal foods that are great sources of vitamin B12 include [13]:

• Meat such as beef and chicken
• Eggs
• Fatty fish such as salmon, tuna, mackerel and trout
• Dairy foods such as milk, yoghurt and cheese
• Shellfish such as oysters and mussels
• Organ meats

Plant-based or fortified sources of vitamin B12

Don't eat meat? Another way to get your dose is through fortified products. These are foods that have added vitamins and nutrients to help improve their nutritional value [14].

Plant-based sources of vitamin B12 include:

• Fortified plant milks such as almond and oat
• Fortified nutritional yeast (which can be sprinkled on other foods)
• Fortified breads
• Fortified breakfast cereals
• Fortified plant-based meat alternatives

It's important to check the labels on these fortified foods to ensure they have actually been enriched with extra vitamin B12 specifically.

Do you need to supplement vitamin B12?

It's important to note that not everyone needs to take vitamin B12 dietary supplements. Only roughly 6 per cent of people under 60, and 20 per cent of people over 60, are deficient in vitamin B12 [15].

When to speak to a doctor about low B12 levels

The only way to know for sure if you're low in vitamin B12 is with a blood test. However, there are a few signs of a vitamin B12 deficiency that you can look out for [16]. These include:

• Fatigue or lightheadedness
• Neurological issues such as numbness, tingling in hands, poor balance or memory problems
• Irritability and low mood
• Digestive issues such as constipation and nausea
• Yellowish or pale skin

Of course, these symptoms can also be associated with many different health issues. So, it's important to speak to your doctor so they can look at the broader picture of what's going on.

Weight loss medications and vitamin B12: What's the connection?

If you're taking a weight loss medication like Wegovy or Mounjaro, this can indirectly increase your risk of a vitamin B12 deficiency. This is because it significantly decreases your appetite, which means it can be difficult to eat enough foods that are rich in vitamin B12 [17]. Potential side effects like vomiting or diarrhoea can also impact vitamin B12 absorption.

This is why it's so important to take a holistic approach to medical weight loss. The Juniper Programme combines weight loss medication with health coaching to ensure you feel your best at every stage of your weight loss journey. With guidance from expert nutritionists, you'll know exactly what to eat to keep your energy levels up — even when you don't feel like it.

You can learn more about the program here.

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