Hair loss often causes anxiety and discomfort, both aesthetic and psychological, for those affected, so much so that it can negatively impact their quality of life. It may be a sign of acute or chronic illnesses, nutritional deficiencies, as well as physical or psychological stress. All of these conditions negatively impact the gastrointestinal system, causing inflammation which can result in increased permeability of the intestinal mucosa. This, in turn, leaves the immune system more vulnerable to foreign proteins.

Today, many studies have shown how the bacteria in our intestines play an active role in the function and composition of the intestinal mucosa. Together all these microorganisms - and we say “all” because there are so many different species (bacteria, intestinal fungi, viruses, and protozoa) - are called the microbiota, from the Greek word meaning “the collection of all living things in an environment”. When this ecosystem is balanced, it is described as being in a state of eubiosis. However, if the intestines’ microorganisms are thrown out of equilibrium, qualitatively or quantitatively, a state of disbiosis arises. These changes can lead to a series of problems both within the intestine and elsewhere in the body.

Our diet, meaning our eating habits, our intestine, and our microbiota are closely interconnected. In particular, the microbiota play a crucial role in our ability to metabolise proteins, carbohydrates, and fatty acids, as well as vitamins and other metabolites. There is even more evidence to prove the connection between intestinal microbiota and the health of our hair. Studies confirm that the microbiota not only support the production of some of the key nutrients that promote hair growth, but they may also regulate the hormones that control the transitions between different phases in the hair life cycle: anagen, telogen, and catagen. It has been noted that, together with other concurrent factors, intestinal disbiosis leads to the development of the various forms of alopecia, which is why intestinal microbiota and their metabolism may be the subject of research for treating hair-related conditions. We can influence the intestinal microbiota and restore eubiosis by eating correctly and using probiotics to regulate both our intestinal defences and overall immune systems, thus improving inappropriate immune response mechanisms.

Hair health is therefore strongly influenced by a range of factors and is tied to a healthy, balanced diet that includes all the nutrients necessary for the production of hair follicle components and keratin synthesis. In fact, when placed under a microscope, the hair of people with an unbalanced diet can be seen to have a smaller diameter and smaller bulbs. It may show thinning or complete loss of the root sheath, which in lay terms, refers to the tissue that keep the hair anchored in the scalp. Considering that hair is made up of 65-95% keratin, a protein, and the rest consists of water, fats, pigments, and oligoelements, we can see that although the hair's protein requirements need to be met first, it's important to also provide the other essential elements. Therefore, a healthy, balanced diet that promotes healthy hair includes the right amount of water: about a litre and a half per day, to keep the scalp moisturised and the hair soft. Proteins and amino acids are also crucial: in particular, cystine and lysine are the two essential amino acids for keratin synthesis. Cystine, a sulphur-containing amino acid, which gives the hair its strength and elasticity, is especially important. Taurine and arginine help nourish the hair follicle bulbs, and can be found in red meat, eggs, and fish. Glycine and histidine, two important components of collagen, improve cell turnover and hair trophism.

The health and wellness of our hair also depends on an adequate supply of oligoelements, especially iron. As a fundamental component in haemoglobin, the molecule that transports oxygen through our blood, this mineral ensures that the scalp and follicles receive the oxygen and nourishment they need. No less important is zinc, which is found in meat and fish and stimulates the immune system, promoting germ cell activity. Magnesium, which is found in cereals, vegetables, dried fruit, and legumes, promotes the synthesis of enzymes that are involved in both the production of melanin and in hair growth. Copper is found in spinach, crustaceans and shellfish, nuts, chocolate, milk and dairy products, and potatoes and contributes to the synthesis of melanin, the substance that gives hair its colour.

Vitamins are especially important because some of them are involved in follicular activity. In some cases, hair anomalies can be traced back to a vitamin deficiency, often the result of restrictive or drastic diets undertaken too lightly.

It seems clearer than ever: we are what we eat, and everyone can see it!




Let's start with vitamin A, also known as Retinol because of its function in the eyes. It is important for the hair because it assists in the formation of mucopolysaccharides, the sugars found in the dermis and in the hair root sheath. It also regulates the synthesis of keratin and has an important, antioxidant effect against free radicals.

Vitamin E is another antioxidant vitamin that combats the free radicals responsible for premature aging of the scalp and hair.

The B vitamins regulate hair follicle metabolism, and they must be introduced into our diets because our bodies cannot produce them autonomously. Vitamin B1 allows the hair to grow healthy and strong; B2 promotes sebum secretion as well as the metabolic processes of the cells and hair follicle, and a B2 deficiency can cause dry scalp; B3 supports healthy energy metabolism, contributing to the integrity of the scalp and hair; B4 stimulates the hair follicles; B5 helps keep the hair shaft robust and accelerates hair re-growth; B6 is involved in protein assimilation and influences the 5-alpha reductase enzyme, inhibiting the transformation of testosterone into DHT; B9 is crucial for the synthesis of proteins and nucleic acids, and a B9 deficiency causes acute telogen effluvium; B12 is found in animal products in the form of a protein complex.

Vitamin H is a water-soluble vitamin that supports the formation of fats and is produced to a minor extent by the intestinal microbiota.

Vitamin D is important for the integrity of the scalp and hair, and a vitamin D deficiency causes hair loss and dermatitis.

Vitamin F consists of a mix of two essential fatty acids, linoleic acid and alpha-linoleic acid together with arachidonic acid. A vitamin F deficiency leads to erythema, dry skin, and flaky scalp, with hair loss as well as depigmentation and dryness of the remaining hair.

Finally, vitamin C is included in more and more cosmetics as a powerful inhibitor of free radical formation and supports the immune system. It also promotes iron absorption.