Functional mushrooms and vitamins – do mushrooms contain vitamins? Scientific research debunks a popular myth.

For years, the belief was repeated that mushrooms are difficult to digest, devoid of nutritional value, and unsuitable for children. Today, scientific research is increasingly clearly showing that many species of functional mushrooms contain valuable vitamins, minerals, and bioactive compounds that support the human body.

One of the most frequently cited scientific publications — “A Review of Mushrooms as a Potential Source of Dietary Vitamin D”, published in the journal Nutrients — demonstrated that mushrooms may be the only non-animal, natural source of significant amounts of vitamin D2 without the need for food fortification.

Researchers emphasize that mushrooms are a natural source of B vitamins, antioxidants, and ergosterol — a compound that converts into vitamin D2 under the influence of UV radiation. Studies have shown that properly prepared mushrooms may contain significant amounts of vitamin D.

Functional mushrooms have been used for centuries in traditional Eastern medical systems, and today they are becoming the subject of intensive research into immunity, the nervous system, cellular energy, and support for the body during oxidative stress.

This is precisely why reishi, Cordyceps militaris, lion’s mane, maitake, shiitake, Agaricus blazei Murill, and chaga are now being intensively studied for their health-promoting properties.

Reishi – a natural source of antioxidants and B vitamins

Reishi, also known as Ganoderma lucidum, is one of the most highly valued functional mushrooms in the world.
Studies indicate that Reishi contains:

• vitamin B2,
• niacin (B3),
• vitamin B5,
• mineral compounds,
• ergosterol, a precursor of vitamin D2.

Reishi is particularly rich in polysaccharides and triterpenes, which exhibit strong antioxidant activity. Scientists are analyzing its potential in supporting immunity, body regeneration, and the protection of cells against oxidative stress.

Cordyceps – the mushroom of energy and physical performance

Cordyceps militaris contains valuable active compounds and vitamins that support the body’s energy metabolism.

Its composition includes, among others:

• vitamin B1,
• vitamin B2,
• vitamin B12,
• vitamin E,
• ergosterol.

Scientific studies indicate that Cordyceps may support cellular energy production and the body’s adaptation to physical and mental exertion. Thanks to the presence of antioxidants and polysaccharides, it is one of the functional mushrooms most commonly chosen by active individuals.

Lion’s Mane – support for the brain and nervous system

Lion’s Mane (Hericium erinaceus) is one of the best-studied mushrooms in terms of its neuroprotective effects.

It contains:

• vitamin B1,
• vitamin B2,
• niacin,
• vitamin D2,
• zinc and potassium.

Studies indicate that compounds present in Lion’s Mane — hericenones and erinacines — may support the synthesis of NGF, or nerve growth factor. As a result, this mushroom is increasingly being analyzed in relation to concentration, memory, and support for the nervous system.

Maitake – the mushroom of immunity and metabolism

Maitake, or Grifola frondosa, stands out for its high content of beta-glucans and vitamins that support metabolism.

It contains:

• vitamin D2,
• vitamins B1, B2, and B3,
• selenium,
• potassium,
• copper.

Scientific studies show that Maitake may support the body’s natural immune mechanisms and help maintain proper metabolism. Thanks to the presence of beta-glucans, it is one of the most highly valued functional mushrooms in modern supplementation.

Agaricus blazei Murill – Brazilian mushroom rich in beta-glucans

Agaricus blazei Murill is a functional mushroom native to Brazil, valued for its high content of polysaccharides and nutrients.

It contains:

• vitamins B1 and B2,
• vitamin D2,
• vitamin E,
• mineral compounds,
• beta-glucans.

Research on Agaricus blazei focuses mainly on its immunomodulatory and antioxidant potential. This mushroom is currently one of the most frequently analyzed species in terms of supporting the body during oxidative stress.

Shiitake – a natural source of vitamin D2

Shiitake is among the most popular functional mushrooms in the world and is one of the best-studied sources of ergosterol.

Its composition includes:

• vitamin D2,
• vitamin B2,
• niacin,
• folates,
• polysaccharides.

Studies have shown that exposing mushrooms to UV radiation increases their vitamin D2 content through the conversion of ergosterol.

This is precisely why functional mushrooms are increasingly being referred to as the “food of the future” — natural, rich in biologically active substances, and capable of supporting the body in a comprehensive way.

Vitamin D2 from functional mushrooms – why is it so important for the body?

Vitamin D plays an extremely important role in the human body. Among other functions, it is responsible for the proper absorption of calcium and phosphorus in the small intestine, supporting the health of bones and teeth. Adequate levels help reduce the risk of osteomalacia in adults and rickets in children. Studies also show that vitamin D supports muscle function and the immune system, and may help reduce the risk of falls in older adults.

An increasing number of scientific publications also indicate that maintaining adequate vitamin D levels may be important for the health of the entire body. Its potential impact on protection against certain neurodegenerative diseases, cardiovascular diseases, type 1 and type 2 diabetes, and selected respiratory conditions is being analyzed. Although some studies still require further confirmation, scientists agree that vitamin D deficiency is now one of the most common deficiencies worldwide.

Although vitamin D is called a vitamin, the body is able to synthesize it on its own under the influence of UV radiation. The problem arises, however, when exposure to sunlight is limited — especially in autumn and winter or when working indoors. It is estimated that as many as one billion people worldwide may have insufficient vitamin D levels, which is why increasing attention is being paid to natural dietary sources of this substance.

One of the most interesting sources of vitamin D2 is functional mushrooms. Mushrooms such as reishi, shiitake, maitake, cordyceps, and chaga contain ergosterol, which converts into bioavailable vitamin D2 from mushrooms under the influence of UV light. Importantly, UV-enriched mushrooms are now recognized as one of the few natural, non-animal sources of vitamin D, which means they may provide particularly valuable support for vegans and vegetarians.

Functional mushrooms – more than ordinary food

Modern research on mushrooms shows that they are not merely a culinary addition. They are a natural source of:

• B vitamins,
• vitamin D2,
• beta-glucans,
• antioxidants,
• bioactive polysaccharides.

An increasing number of scientific publications confirm the potential of functional mushrooms in the context of immunity, metabolic health, the nervous system, and protecting the body against oxidative stress.

That is why the claim that “mushrooms contain no vitamins” is no longer supported by current scientific literature.

Source: A Review of Mushrooms as a Potential Source of Dietary Vitamin D, PubMed