Spanish scientists create food supplement 500 times richer in Vitamin D

Image of the team of scientists from La Rioja University.

Image of the team of scientists from La Rioja University. Credit:

A team of scientists from from the University of La Rioja have created a food supplement that is 500 times richer in Vitamin D.

This vitamin plays an integral role in our body in maintaining healthy levels of calcium and phosphorus. As a result, the human body benefits from a normal metabolism, neuromuscular transmission and bone mineralisation.

It also helps to prevent osteoporosis, a disease that causes bones to become thinner and weaker, making them more brittle and likely to suffer fractures.

Vitamin D deficiency is also related not only to rickets and osteomalacia, but also to an increased risk of other diseases. These include diabetes mellitus, obesity, cancer and infectious diseases, including Covid-19.

The synthesis of this vitamin in our skin is activated by exposure to the sun, which is why its decrease is normally more frequent in winter.

How many foods contain Vitamin D naturally?

Very few foods contain vitamin D naturally. Among them are fatty fish (such as salmon or tuna), liver, cheese, and egg yolk.

These are all foods derived from animals, which results in vegetarians and vegans finding it difficult to maintain good levels of vitamin D.

This relative scarcity of vitamin D in the diet explains why it is increasingly present in food supplements, especially those made from mushrooms.

Mushrooms are an excellent source of vitamin D, although their content is lower compared to other foods. The shiitake mushroom can contain a significant amount of this vitamin, with around 40 IU per 100 grams.

As explained by Encarnación Núñez: ‘In this context, the enrichment of vitamin D in mushrooms exposed to UV-B radiation is an interesting alternative’.

‘Since its vitamin D content is relatively high among non-animal sources, it may alleviate deficiency in humans and represent a primary source of vitamin D for vegans’, the scientist continued.

What have the team achieved?

Encarnación and his colleagues from the University of La Rioja have achieved just that, a technology capable of obtaining mushrooms enriched with vitamin D2 through ultraviolet light irradiation.

Even more pleasing is the fact that these enriched mushrooms can be used to alleviate the deficiency of this vitamin through dietary supplements.

Risk groups for vitamin D deficiency include pregnant women, exclusively breastfed infants, older people, people who are obese or have absorption disorders, and those with dark skin or who get little exposure to the sun.

Their study – the results of which were published in the scientific journal LWT – Food Science and Technology – has produced products such as capsules (600 mg) of fortified shiitake powder.

These contain an amount of vitamin D equivalent to the minimum daily intake for adults. In addition, the researchers stressed that the technology used was easy to adapt to the market and provided safe and economical nutritional supplements.

Shiitake mushrooms are 500 times richer in vitamin D

The team’s work focused on three mushrooms: shiitake (Lentinula edodes), oyster mushroom (Pleurotus eryngii) and Portobello mushroom (Agaricus brunnescens).

These three species, from organic production, were subjected to UV-B radiation in different doses and preparations (fresh slices and dry powder), in a semi-industrial facility of their own design.

‘All treatments produced a significant increase in vitamin D2 in the mushrooms, especially in the shiitake powder, where it increased up to 500 times, maintaining the rest of its nutritional composition’, explained Núñez.

Following microbiological analysis to ensure safe consumption, this enriched shiitake powder was encapsulated. Over a two-month period they studied how its intake affected the bioavailability of vitamin D2 in humans. It was proven that this dietary supplement maintained vitamin D at adequate levels.

The study was carried out as part of a doctoral thesis currently in development. It involved researchers from the Plant Ecophysiology, Climate Change and Environment Group of the University of La Rioja.

They were joined by scientists from the Infectious Diseases, Microbiota and Metabolism Unit of the Biomedical Research Centre of La Rioja (CIBIR).

There was also collaboration by the private sector, such as the Riojan technology-based company Clean-Biotec, and was financed by the Economic Development Agency of La Rioja (ADER).

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Written by

Chris King

Originally from Wales, Chris spent years on the Costa del Sol before moving to the Algarve where he is a web reporter for The Euro Weekly News covering international and Spanish national news. Got a news story you want to share? Then get in touch at