Mushrooms are #1 Vitamin B monsters (The Ultimate Guide)

July 31, 2021

mushrooms and vitamin B

Everything your mother never told you about Vitamin B. Oyster mushrooms is a plant-based food that covers the Vitamin B group with the exception of B12. But, 50g dried Shiitake gives the daily recommended amount.

In this post...

Quick mushroom Facts

  • Oyster mushrooms are a great source of the Vitamin B group, with the exception of B12.
  • …However, Shiitake is one of the few mushrooms with elevated B12. 50g of dried Shiitake will meet your daily requirements.
  • For people on a plant-based diet, B12 is difficult to access because it is made in the gut of animals. So, plant foods are not a source of B12 unless they are fortified.
  • It is thought that Shiitake is able to access bacteria in order to make B12.

Oyster Mushrooms and the B group

Oyster mushrooms are one of the best sources of the B complex because they can make most of the B group with the exception of B12. But, check out the Shiitake below, they are B12 monsters.  [Source Biosynthesis of vitamins B by the fungus Pleurotus ostreatus in a submerged culture E F Solomko, G S Eliseeva]

What B group vitamins are in an Oyster Mushroom?

1 cup (86g) raw (fresh) Oyster Mushrooms contain

B1 (Thiamin) 0.108 mg 9.00%
B2 (Riboflavin) 0.3 mg 23.08%
B3 (Niacin) 4.262 mg 26.64%
B5 (Pantothenic acid) 1.113 mg 22.26%
B6 (Pyridoxine) 0.095 mg 7.31%
B9 (Folate) 33 µg 8.25%

Source USDA https://fdc.nal.usda.gov/fdc-app.html#/food-details/1750345/nutrients

In general Oyster mushrooms are a nutritional powerhouse, see the USDA nutritional breakdown to learn more.

Shiitake & Vitamin B12

B12 is generally low across most varieties of mushrooms and completely absent from plant sources. However, Shiitake is able to produce it in good amounts. 100 g of dried Shiitake significantly varied in B12 content however, the average being approximately 5.61 μg which is still twice the daily recommended value. [Source Vitamin B12-Containing Plant Food Sources for Vegetarians Fumio Watanabe,* Yukinori Yabuta, Tomohiro Bito, and Fei Teng].  With the recommended daily amount of B-12 for adults being 2.4 micrograms [ source ] a 50g helping of dried Shiitake should meet daily requirements.

 Types of vitamin B

Here’s everything you should know about the eight types that make up the B group:

  • B1 (thiamin)
  • B2 (riboflavin)
  • B3 (niacin)
  • B5 (pantothenic acid)
  • B6 (pyridoxine)
  • B7 (biotin)
  • B9 (folate or ‘folic acid’ when included in supplements)
  • B12 (cyanocobalamin).

B1 (Thiamin)

B1 helps to convert glucose into energy and has a role in nerve function.

Good sources of thiamin

  • Mushrooms
  • wholemeal cereal grains
  • seeds (especially sesame seeds)
  • legumes
  • wheatgerm
  • nuts
  • yeast

B1 deficiency

In the west, B1 deficiency is rare because it’s generally found in countries where white rice is the dietary staple. In the Western world, deficiency is usually caused by excessive alcohol intake or a very poor diet. Alcohol reduces B1 absorption in the gut and increases its excretion from the kidneys. Symptoms include – confusion, irritability, poor arm or leg (or both) coordination, lethargy, fatigue and muscle weakness.

A condition called Beriberi is caused by B1 deficiency and affects the cardiovascular, muscular, gastrointestinal and nervous systems. It can be classified as ‘wet’ and ‘dry’ beriberi. ‘Dry’ beriberi affects the nervous symptom while ‘wet’ beriberi affects the cardiovascular system.

Wernicke-Korsakoff syndrome (also called ‘wet brain’) is another B1 deficiency disease linked to alcohol excess and a thiamin-deficient diet.

Riboflavin (B2)

Riboflavin is primarily involved in energy production and helps vision and skin health.

Good sources of B2

  • Mushrooms
  • yeast
  • wholegrain bread and cereals
  • leafy green vegetables
  • animal-based: milk, yoghurt, cottage cheese, egg white, meat, liver, kidney

B2 deficiency (ariboflavinosis)

B2 deficiency (or ariboflavinosis) is rare and is usually seen along with other B-group vitamin deficiencies. People with high alcohol consumption and people who do not consume dairy (so perhaps a concern for vegans) products are at most risk.

Niacin (B3)

B3 is essential for the body to convert carbohydrates, fat and alcohol into energy. It helps maintain skin health and supports the nervous and digestive systems. Unlike other B-group vitamins, niacin is heat stable so little is lost in cooking.

Good sources of B3

  • Mushrooms
  • wholegrain bread and cereals
  • nuts
  • other protein-containing foods.
  • animal-based: meats, fish, poultry, milk, eggs

B3 deficiency (pellagra)

People who drink excessive amounts of alcohol or live on a diet almost exclusively based on corn are most at risk of pellagra. Other causes are associated with digestive problems where the body does not absorb B3 efficiently.

The main symptoms of pellagra are dementia, diarrhoea and dermatitis. This disease can lead to death if not treated.

Excessive B3 intake

Large doses of B3 produce a drug-like effect on the nervous system and on blood fats. While favourable changes in blood fats are seen. (In fact, a common cholesterol-lowering drug uses niacin.) Side effects can include – flushing, itching, nausea and potential liver damage.

Pantothenic acid (B5)

B5  is also needed to metabolise carbohydrates, proteins, fats and alcohol as well as produce red blood cells and steroid hormones.

Good sources of B5

B5 is widespread and found in a range of foods, but some good sources are usually: liver, meats, milk, kidneys, eggs, yeast, peanuts and legumes.

B5 deficiency

Because B5 is found in such a wide variety of foods, deficiency is extremely rare.

B6 (pyridoxine)

B6 is needed for carbohydrate & protein metabolism, the formation of red blood cells and certain brain chemicals. It influences brain processes and development, immune function and steroid hormone activity.

Good sources of B6

  • Mushrooms
  • cereal grains
  • legumes
  • nuts
  • green and leafy vegetables
  • fruit.
  • animal-based: fish and shellfish, meat and poultry, liver

B6 deficiency

B6 deficiency is rare. Again, people who drink excessive amounts of alcohol, women (especially those on the contraceptive pill), the elderly and people with thyroid disease are the most at risk.

Excessive B6 intake

B6 toxicity is mostly due to supplementation and can lead to harmful levels in the body that can damage the nerves.

B7 (Biotin)

B7 is needed for energy metabolism, fat synthesis, amino acid metabolism and glycogen synthesis. High B7 intake can contribute to raised blood cholesterol levels.

Good sources of B7

  • mushrooms
  • cauliflower
  • yeast
  • peanuts
  • animal-based: liver, chicken, egg yolks

B7 deficiency

Biotin deficiency is very rare. It’s widely distributed in foods and only required in small amounts. Over-consumption of raw egg whites over periods of several months (by bodybuilders, for example) can induce deficiency because a protein in the egg white inhibits biotin absorption.

B9 (Folate or folic acid)

B9 is used to form red blood cells. It helps the development of the foetal nervous system, as well as DNA synthesis and cell growth. This is why pregnant women are often prescribed a supplement.

Good sources of B9

  • Mushrooms
  • cereals
  • citrus fruits.
  • green leafy vegetables
  • legumes
  • seeds
  • animal-based: liver, poultry, eggs

Excessive B9 intake

B9 is generally considered non-toxic. However, excessive intakes (above 1,000 mcg per day) over a period of time can lead to malaise, irritability and intestinal dysfunction. The main risk with excessive folate intake is that it can mask a B12 deficiency. So, it’s best to consume these two vitamins within the recommended amounts.

B12 (Cyanocobalamin)

As most vegans know, B12 is one of the hardest (so most important) micronutrients to get while on a plant-only diet. B12 produces & maintains the myelin surrounding nerve cells, mental ability, red blood cell formation and the breaking down of fatty & amino acids to produce energy. B12 has a close relationship with folate, both depend on one another to work properly.

Why it’s hard to get from a plant diet is because B12 is made and stored in the gut of animals (actually it’s made by gut bacteria) Source. It is particularly found in the flesh of predators. So plant foods are not a source of B12 unless they are fortified, with fortified breakfast cereals ranking as the top source of B12. For this, manufacturers use B12 produced from yeast.

Because B12  plays a key role in DNA replication, obtaining sufficient amounts is essential for every cell in the body. The recommended daily intake of B12 is 2.4mg per day to ensure a wide range of health benefits including energy production, regulation of the nervous system, reduction of cardiovascular disease, encouraging optimal digestion and essential for hair, skin and nails.

Good sources of B12

  • Shiitake mushrooms
  • animal-based: almost anything of animal origin, liver, meat, milk, cheese, eggs

B12 deficiency

Because B12 is only found in foods from animal sources, people following strict vegan diets, as well as breastfed babies of vegan mothers, tend to be most commonly affected.

Absorption of B12 from the gut also tends to decrease with age, so the elderly is another group who are more at risk of deficiency.

Much of the information in this section has been sourced from the better health channel of the Victorian Govt. (Aust.) https://www.betterhealth.vic.gov.au/health/healthyliving/vitamin-b#types-of-vitamin-b

How much B complex do you need?

For women

the recommended daily intake is:

For men

the recommended daily intake is:

Older Adults and pregnant women require higher amounts of B vitamins.

Health conditions affecting B group absorption

Certain underlying health conditions can prevent your body from properly absorbing B vitamins.

  • celiac disease
  • HIV
  • Crohn’s disease
  • alcohol dependence
  • kidney conditions
  • rheumatoid arthritis
  • ulcerative colitis
  • inflammatory bowel disease

Further reading on Mushrooms and B group vitamins

Brent Williams

Brent Williams (MBA, MGSM) is a former digital architect for scientific publisher Reed Elsevier turned regenerative mycologist. He applies decades of high-level technical precision to the craft of commercial mushroom cultivation at Mycobio, helping Kiwis reconnect with functional nutrition and sustainable farming. Want to know more about the science and story behind Mycobio? Read More About Brent

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