B vitamins: Everything You Need To Know

What are B vitamins?

B vitamins are a group of water-soluble vitamins that play an important role in many bodily functions. B vitamins assist with foetal development, healthy hormones, neurotransmitters, stress management and energy production.

Because B vitamins are water-soluble, this means they need to be replaced regularly. Most people can get the B vitamins they need by eating a varied and balanced diet. However, some populations are at risk of B vitamin deficiency which can manifest in all kinds of symptoms and conditions.

Here are all the B vitamins:

- B1 (Thiamine)

- B2 (Riboflavin)

- B3 (Niacin)

- B5 (Pantothenic Acid)

- B6 (Pyridoxine)

- B7 (Biotin)

- B9 (Folic Acid/Folate)

- B12 (Cobalamin)

What are the best food sources of B vitamins?

In general, getting your B vitamins from food is the best way to ensure you're getting the right amount. The best food sources of B vitamins include: 

- leafy green vegetables

- salmon

- meat and poultry

- legumes

- nuts and seeds

- whole grains

- dairy products

- eggs

Why are B vitamins so important?

The word 'essential' couldn't be overstated when it comes to B vitamins. Unlike other vitamins, the body can't store B vitamins and as such, they need to be replenished often to maintain good health. As mentioned, some of the key functions of B vitamins include energy production, red blood cell formation, nervous system function and the synthesis of DNA.

So... B vitamins seem relatively important then.

Now, let's dive into each B vitamin, what they do and where to get them in your diet. 

Starting from the top...

Vitamin B1: Thiamin

Thiamin, or vitamin B1, is a water-soluble vitamin that is essential for human health. It is involved in various bodily functions, including energy production, carbohydrate metabolism and nerve function. B1 is mainly found in foods like pork, beef, whole grain products and legumes.

While very rare in developed countries, extreme thiamin deficiency is known as Beriberi. This condition is characterised by a range of symptoms, such as peripheral neuropathy, cardiac oedema and impaired cognition. Generally speaking, it's easy enough to get thiamin from the diet. Vitamin B1 is commonly found in fortified foods too.

Vitamin B2: Riboflavin

Riboflavin, or vitamin B2, is also involved in energy production and metabolism, as well as the maintenance of healthy skin and eyes. B2 is integral to the metabolism of iron and vitamin B6. Vitamin B2 can be found in foods like milk, cheese, eggs and leafy green vegetables.

Vitamin B3: Niacin

Niacin, or vitamin B3, is an important nutrient for human health. It is involved in mitochondrial energy production and healthy skin and nerve function. B3 is made from the amino acid tryptophan and can be found in foods like meat, poultry, fish, eggs and dairy products.

Severe niacin deficiency is known as pellagra, which is relatively rare. However, it historically occurred in South American cultures or in poorly developed countries. Classically, pellagra can manifest as dermatitis, diarrhoea and in chronic cases, dementia. 

Vitamin B5: Pantothenic Acid

Pantothenic acid, or vitamin B5, is involved in the metabolism of fats and carbohydrates, as well as the production of red blood cells and hormones. B5 can be found in a variety of foods, including meat, poultry, fish, vegetables, legumes and whole grain products.

Vitamin B6: Pyridoxine

Pyridoxine, or vitamin B6, is involved in a range of biochemical reactions in the body. B6 is involved in the metabolism of amino acids, carbohydrates, and fats. B6 is also necessary for the synthesis of nucleic acids (DNA and RNA) and red blood cells. It's needed for proper nerve function and immune system function. Finally, B6 is involved in the release of glucose from glycogen (the stored form of glucose in the liver). It’s also required for the metabolism of tryptophan (the amino acid precursor to serotonin, a neurotransmitter).

Generalised B6 deficiency presents as anaemia, dermatitis (skin inflammation), depression, confusion, and seizures. Severe pyridoxine deficiency is rare but can lead to a condition known as sideroblastic anaemia. This is a type of anaemia characterised by the presence of iron-containing granules in red blood cells.

Fortunately, B6 is found in foods like beef, poultry, fish, potatoes, starchy vegetables, lentils, non-citrus fruits and fortified cereals. So, it's easy enough to be replete in B6 if you're eating a balanced diet.

Vitamin B7: Biotin

Biotin, or vitamin B7, is involved in the metabolism of fats and carbohydrates, as well as the production of energy. Biotin is present in food items like eggs, meat, poultry, fish, nuts and legumes.

Biotin deficiency is relatively rare but can cause problems like hair loss, skin rash and brittle nails. Biotin supplementation is sometimes used as a treatment for alopecia, with some varying results according to the research.

Vitamin B9: Folate

Folate, or vitamin B9, is involved in cell growth and repair, erythropoiesis (red blood cell formation), the conversion of homocysteine to methionine and DNA synthesis.

Folate is particularly important for pregnant women as it helps to prevent birth defects of the brain and spine, such as spina bifida. It's well established that folate is essential in foetal development. However, in adults, folate insufficiency can also lead to health problems. Folate deficiency can lead to a condition known as megaloblastic anaemia, where red blood cells are large and abnormally shaped. This condition can cause fatigue and weakness, yet luckily can be ameliorated with an increased intake of folate-rich foods. 

B9 is found in dark leafy green vegetables, legumes, nuts and seeds. Folic acid is the synthetic form of vitamin B9 or folate, which is found in fortified cereals, bread and pasta as well as in supplements. Often, folic acid is poorly absorbed and therefore, it’s better to obtain folate in its natural form in food. Have a read of this for more on folate and the recommended intakes for different populations.

Vitamin B12: Cobalamin

Cobalamin, or vitamin B12, is involved in the metabolism of proteins and fats, as well as the synthesis of DNA and blood cell formation. It's incredibly important for the proper function of the brain and nervous system. B12 is also essential in pregnancy as it, too, helps prevent neural tube defects.

B12 deficiency is relatively rare but can cause symptoms including anaemia, fatigue, weakness and musculoskeletal pain. Importantly, B12 deficiency can cause nervous system issues, such as cognitive decline, peripheral neuralgia, tingling and memory loss.

B12 is found naturally in animal products, including meat, poultry, fish, eggs, and dairy. As vitamin B12 is found exclusively in meat and eggs, it's common to see deficiency symptoms in followers of long-term vegan diets. B12 supplementation is often used to treat B12 deficiency. It can also be made synthetically and added to foods such as cereals and energy bars.

What are the common signs and symptoms of B vitamin deficiency?

B vitamin deficiencies can cause a range of different symptoms, depending on which vitamin is lacking. Common signs and symptoms of B vitamin deficiencies include:

• fatigue
• weakness
• irritability
• nausea
• vomiting
• muscle cramps
• anaemia
• difficulty breathing
• heart palpitations
• pale skin
• hair loss
• mouth ulcers
• sore tongue
• visual problems

Who is at risk for B vitamin deficiency?

Pregnant women, young children and those with chronic health conditions are at the greatest risk of developing B vitamin deficiencies. During pregnancy and early development, there is rapid growth and the body's demand for B vitamins is particularly high. In extreme chronic conditions, B vitamins are depleted which causes a deficiency state in some people.

Other groups of people who may be at risk for B vitamin deficiency include:

• Chronic kidney disease or liver disease sufferers
• The elderly
• Chronic smokers
• People who have had weight-loss surgery
• Alcoholics
• People with eating disorders
• Those with malabsorption disorders such as coeliac disease
• People taking medications such as the oral contraceptive pill (OCP), antibiotics and anticonvulsants

Can you have too many B vitamins?

You might be wondering if it's possible to have too many B vitamins since they're so essential for our health. The short answer is yes, it is possible to have too much of a good thing when it comes to B vitamins. The likely culprits of B vitamin 'toxicity', however, are the synthetic kinds found in fortified foods. Hence why I'm not necessarily a fan of them.

Too much of specific B vitamins can lead to side effects such as:

• Diarrhoea
• Headaches
• Nausea
• Skin rashes and flushing 

If you are taking a supplement that contains B vitamins, it's important to follow the recommended dosage and ideally, be guided by a trusted health provider.

B vitamins are important for energy and vitality

B vitamins are essential for human health. They play a role in foetal development, hormone function, neurotransmitter synthesis, stress management and energy production. B vitamin deficiencies can range from mild nuisances to more severe impairments. Ensuring you're eating a well-balanced diet full of nuts, seeds, meat, seafood and wholegrains will give you the best chance of getting enough of these vitamins for optimal health and wellbeing.