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Struggling with fatigue and brain fog?

You may need these B vitamins…

B vitamins are a group of eight individual B vitamins, each equally as important as the other. They are essential for the body to function efficiently, helping to boost energy, focus and mood.

B vitamins are needed to keep cells well oxygenated to prevent fatigue, transport nutrients around the body and maintain a healthy nervous system. They also help make hormones like serotonin and melatonin to keep mood and sleep cycles in check.

If you’re struggling with fatigue and brain fog, you could be deficient in certain B vitamins. Find out what each B vitamin does, how they can improve your health and which foods to find them in.

What do B vitamins help with?

The body needs a certain amount of B vitamins daily to function efficiently. They must be acquired from a dietary source or in supplemental form as the body cannot make B vitamins, except for niacin (B3).

B vitamins are water-soluble which means they dissolve in water and are easily absorbed. However, they aren’t stored in the body (unlike fat-soluble vitamins), so your body uses what it needs and excretes the rest via urine.

B1 (Thiamine) – The Energy Booster

Thiamine (B1) was the first B vitamin to be discovered and one of its main functions is producing cellular energy by converting food into “fuel” to power your cells and give you energy. B1 also helps build lean muscle mass, increases blood flow (to improve cardiovascular function), strengthens the immune system and keeps your nervous system healthy by enabling nerves to communicate with each other.

Even though deficiency is rare in the developed world, signs and symptoms include:

  • Red, painful tongue, mouth ulcers
  • Fatigue, low mood and depression
  • Headaches, memory loss

Food sources of B1

  • Pine nuts, macadamia nuts
  • Sunflower seeds, flaxseeds
  • Peas, asparagus
  • Black beans, navy beans
  • Nutritional yeast (savoury, cheesy-flavoured flakes that are loaded with nutrients and can be sprinkled over food/ added to cooking. It is available in health shops and from most online food retailers).
  • Eggs (opt for organic)
  • Trout, salmon, liver

Nuts and seeds are best soaked overnight for at least 7 hours as it activates enzymes within the nuts and seeds to aid absorption and enable better digestion. Discard the water afterwards. 

Soaking dried beans overnight speeds up cooking time and breaks down some of the fibres in the beans, making them easier to digest.

B2 (Riboflavin) – Stops toxins damaging cells

Riboflavin (B2) works as an antioxidant, meaning it protects cells from toxin damage. It works in tandem with the other B vitamins to help maintain the body’s energy supply and prevent fatigue. B2 is also crucial for growth and development, especially in children, as it promotes normal vision and stimulates the growth of bones, skin and hair.

B2 deficiency signs include an inflamed tongue, sores in the corners of the mouth and scaly dermatitis.

Food sources of B2:

  • Green leafy vegetables, spirulina
  • Broccoli, asparagus
  • Whole grains – brown rice, wild rice, oatmeal
  • Nuts, seeds, quinoa
  • Eggs

Opt for organic where possible to reduce your exposure to harmful pesticides, herbicides and chemicals that wreak havoc in the body. This is especially important when consuming fruits, vegetables and animal-derived foods.

Learn which fruits and vegetables are most contaminated with pesticides

How to remove pesticides from your produce

B3 (Niacin) – Enhances memory and focus

Niacin (B3) is the only B vitamin that can be produced in the body from other nutrients. One of the main functions of B3 is to support brain function by protecting brain cells from stress, inflammation and damage. It can also repair damaged cell DNA so cells can function efficiently. Severe niacin deficiency is linked to cognitive decline, memory loss, brain fog and dementia. B3 also aids energy production (converting food to energy for cells), promotes healthy cholesterol levels and improves cardiovascular function (it has shown to reduce blood pressure and heart attack risk).

Mild B3 deficiency signs include:

  • Unrelenting fatigue
  • Vomitting, indigestion
  • Low mood, depression
  • Mouth ulcers, red tongue, inflamed gums
  • A sensitivity to strong light

Severe deficiency causes a condition called pellagra which is characterised by a dermatitis-like rash around the collar, along with diarrhoea and dementia. It is common in Africa, Indonesia and China and among those with anorexia nervosa, Crohn’s, inflammatory bowel disease and alcohol dependency where nutrition and protein consumption is compromised.

Food sources of B3:

  • Mushrooms (especially maitake)
  • Leafy greens, spirulina
  • Nuts, seeds, beans and lentils
  • Whole grains (brown rice, wild rice)

B5 (Pantothenic Acid) – Combats stress and anxiety

Pantothenic acid (B5) is called the anti-stress vitamin as it can combat the damaging effects of stress by regulating stress hormones. B5 gets used up quickly by the body when under stress. When the body has adequate amounts of B5, it is able to cope with stress and anxiety much better.

B5 is required to make an enzyme called coenzyme A that is needed for hundreds of chemicals reactions in the body including energy production and supporting the nervous system. It enables nerves to transmit messages to each other which is important for mood regulation, controlling emotions, brain growth and development, memory, movement and breathing.

Known to reduce inflammation and promote radiant skin and hair, B5 is often added to skincare products to boost skin health. B5 also has anti-histamine properties and is helpful for those with allergies.

B5 deficiency is rare as it found in many food sources, although it can become depleted with high alcohol consumption, prolonged stress and recent surgery (as B5 supports wound healing).

Deficiency signs include:

  • A burning sensation in the feet, tender heels, numbness
  • Fatigue, insomnia, irritability, restlessness
  • Abdominal issues – vomiting, nausea, stomach cramps

Food sources of B5:

B5 is found is almost all foods, however, the richest food sources include:

  • Shiitake mushrooms, avocados, tomatoes
  • Sunflower seeds, peanuts
  • Lentils, beans, whole grains
  • Animal foods –meat, poultry, fish, eggs (opt for organic)

B6 (Pyridoxine) – Regulates mood and improves sleep

The primary action of Pyridoxine (B6) is maintaining a healthy nervous system. It is needed to make the hormones serotonin and melatonin which are the main hormones involved in mood regulation and promoting a healthy sleep cycle.

B6 also boosts the immune system and protects the body from infections by making antibodies. It plays a role in brain development, energy production and producing red blood cells (to prevent fatigue and anaemia). B6 is involved in over 100 chemical reactions in the body and lots of other nutrients depend on it to function.

Higher levels of B6 are needed in pregnancy (particularly in the third trimester when the baby grows significantly), those taking the OCP (oral contraceptive pill), ongoing high stress, hormonal imbalances, inflammatory bowel conditions and alcohol dependency (as B6 becomes depleted).

B6 deficiency signs include:

  • Anaemia, fatigue
  • Depression, mood swings
  • Irritability, confusion
  • Morning sickness and nausea
  • Inflamed mouth and tongue
  • Recurrent mouth sores
  • Skin lesions and dermatitis
  • Hormonal imbalance (especially PMS)

Food sources of B6:

B6 is found in many food sources but food processing, heating and light exposure can reduce B6 levels. The highest sources of B6 include:

  • Dark leafy greens (kale, rocket, spinach)
  • Avocado, sweet potato
  • Bananas, papayas, cantaloupe
  • Sunflower seeds, pistachios, walnuts
  • Whole grains, chickpeas, lentils
  • Beef, liver, poultry, salmon, tuna

B7 (Biotin) – Promotes hair growth and radiant skin

Like other B vitamins, Biotin helps maintain a healthy nervous system and is required for energy production. Another key action of Biotin is promoting healthy skin, nails and hair which is why you find it in hair/skin supplements and skincare products. It has shown to improve shine and volume of hair and strengthen hair by stimulating keratin production and increasing follicle growth so it is great for those experiencing hair loss, dandruff and dry hair/scalps. Biotin also aids blood sugar regulation (especially when used in combination with the mineral chromium) and regenerates tissues when damaged.

Biotin deficiency signs include:

  • Dermatitis and dry, scaly/flaky skin and scalp
  • Hair thinning and hair loss
  • Skin depigmentation
  • Smooth pale tongue

The absorption of biotin may be compromised by prolonged antibiotic use, alcohol and anticonvulsant drugs.

Food sources of Biotin:

  • Egg yolk
  • Bananas
  • Nuts and seeds
  • Nutritional yeast
  • Wholegrains, beans, lentils
  • Cauliflower, broccoli, avocados
  • Sweet potato, mushrooms
  • Organ meats and oily fish

B9 (Folate/ Folic acid) – Slows down ageing and repairs cells

Vitamin B9 is commonly referred to as folate or folic acid. Folate is the natural form found in nature, whereas folic acid or folinic acid (the active form) are synthetic forms found in nutritional supplements. B9 works closely with vitamin B12 to support the nervous system, synthesise new cells and DNA, repair damaged cells, make red blood cells and digest proteins. It is also essential for embryo health and the development of the neural tube (this later becomes the baby’s spinal cord, spine and brain) – this is why folic acid supplements are recommended for preconception and pregnancy.

B9 deficiency signs include:

  • Skin and digestive issues
  • Poor immune function
  • Mood disturbances
  • Inflamed and painful tongue
  • Growth problems
  • Anaemia, fatigue

Food sources of B9 include:

  • Green leafy vegetables (spinach, kale, watercress)
  • Broccoli, Brussels sprouts, asparagus, spirulina
  • Fresh fruit especially oranges
  • Lentils, beans, brown rice
  • Sunflower seeds, beans
  • Nutritional yeast, Brewer’s yeast
  • Seafood, liver, beef

B12 (Cobalamins) – Prevents anaemia and fatigue

B12 is made up of a group of compounds called cobalamins that work together to exert specific actions in the body. B12 is an essential nutrient meaning it needs to come from food as your body cannot make it on its own. B12 has numerous important functions in the body including making red blood cells to ensure body tissues are well oxygenated and prevent anaemia. B12 also stops nerve tissue damage, helps produce cellular energy, regulates mood, protects the heart, bones and brain, slows down cell ageing and aids liver detoxification.

Despite the vitamin being present in many foods, B12 deficiency or insufficiency is quite common, especially in vegans due to limited dietary intake (most food sources of B12 come from animal sources). Other causes include malabsorption due to gut problems, inflammation, trauma or infection, certain medical conditions and medication use.

Deficiency signs include:

  • Tingling, poor balance, dizziness, pins and needles
  • Anaemia (due to poor red blood cell formation)
  • Fatigue, irritability, poor appetite
  • Mood swings, depression, attention problems
  • Inflamed, sore tongue and mouth, mouth ulcers

Food sources of B12 include:

  • Chlorella (a type of algae that comes in powder form)
  • Nori, kelp, dulse and Korean purple laver (a type of seaweed)
  • Nutritional yeast
  • Shiitake and Lion’s mane mushrooms
  • Meat, poultry and fish (especially sardines, mackerel and wild salmon)
  • Dairy products and eggs (opt for organic)

How much B vitamins do you need?

The recommended dietary allowance (RDA) of B vitamins for adults is as follows:

VitaminMen (p/day)Women (p/day)
B1 – Thiamine1.2 mg1.1 mg
B2 – Riboflavin1.3 mg1.1 mg
B3 – Niacin16 mg14 mg

17 – 18 mg in pregnancy/ lactation

B5 – Pantothenic acid5 mg5 mg

6 – 7mg in pregnancy/lactation

B6 – Pyridoxine1.3 – 1.7 mg1.3 – 1.5 mg
B7 – Biotin30 mcg30 mcg

35 mcg during lactation

B9 – Folate/ Folic acid200 mcg200 mcg

400 mcg in pregnancy

B12 – Cobalamins2.4 mcg2.4 mcg

2.6 – 2.8 mcg in pregnancy/lactation

Please note that these reference ranges are for guidance only. If you have a deficiency/ insufficiency or health condition, higher doses (in supplement form) may be required. Speak to a natural health practitioner who can advise you accordingly.  

To learn more about vitamins and minerals, take a look at CNM’s short online courses Nutrition for Everyday Living and Vegan Nutrition for Everyday Living.

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Blog/Article content reflects the author's research and diverse opinions, not necessarily CNM's views. Items may not be regularly updated, so represent the best available understanding at the time of publication.

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