It is composed of 90% rigid keratin, much stronger than that of other skin appendages (hair and body hair). Keratin is a protein, belonging to the family of fibrous proteins, made up of sulfur amino acids, including methionine and cystine. This protein constitutes the material composing the translucent and hard part of the nails. It ensures their solidity, their protection, their growth and their impermeability. Keratin proteins are made by cells in our body from certain vitamins, amino acids, minerals (calcium, selenium, zinc) that we consume.

The nail also contains small amounts of water, fatty acids, calcium (the main mineral constituent of the nail) and iron.

The first role of the nail is a passive role, as a defense against external attacks . The nails prohibit the dorsal surface of the fingers and toes from pressures, shocks, and temperature variations.

The nail also has roles in cooperation with the skin:

• The nail makes the skin of the end of the finger harder by exerting a counter-pressure in relation to the pulpy part. This makes it easier and more efficient to pick up small objects.

• They also play a role in the sensitivity of our sense of touch, due to the intensity of innervation and vascularization of the nail bed.

Today, the nails also have an aesthetic role, serving as a support for varnish, in particular.

• soft nails

Soft nails are usually flexible and bend easily. They are due to demineralization of the nail and a protein deficiency. A deficiency in sulfur, vitamin B, and calcium can also be responsible.

Having your hands too long in water, for example when washing dishes, or washing your hands too often are some causes of soft nails. Indeed, some household products are highly harmful to nail health, so it is necessary to avoid direct contact. So remember to wear gloves.

• The brittle nails

The nails sometimes tend to break or split slightly to the side. This is due to skin dryness and keratin damage caused by frequent contact with water and detergents. Brittle nails can also be a sign of a vitamin, calcium or iron deficiency.

If your nails are brittle, it is better not to cut them. Instead, use cardboard nail lime to gently even out the surface. You must absolutely ban metal files which deteriorate the keratin and further weaken your nails.

• split nails

Nails split when the layers of keratin separate. They are sometimes a sign of a deficiency in vitamins and minerals.

But more often than not, this problem occurs as a result of poor nail filing technique. You can also use a nail polisher to prevent splitting and flaking. Nail biting (onychophagia) is also a risk factor for splitting nails. The application of an anti-gnaw varnish is the best solution to get rid of this bad habit.

• ridged fingernails

The ridges on the nails are, in a way, wrinkles. They are caused by the aging of the nails and are sometimes due to a deficiency in selenium, iodine, iron and vitamin B. Hormonal problems or stress can be associated with it.

Some manicure products and techniques can have harmful effects on the nails. For example, excessive use of a sander can soften the nail and cause scratches to appear. If you have damaged and ridged nails, avoid too aggressive manicure products. Favor, for example, mild solvents, without acetone, in order to avoid drying out your nails and aggravating the situation when you degrade your varnish.

• The proteins :

Made up of amino acids such as methionine and cysteine, they are necessary for the formation of keratin, which naturally strengthens our nails. They are provided by fish, eggs, meats, whole grains, legumes and dairy products.

• Vitamins:

Vitamin A helps strengthen nails. It is particularly concentrated in certain foods of animal origin such as fish and dairy products.

Vitamin B2 or riboflavin is one of the essential vitamins that our body needs. It is linked to the production of keratin, a major constituent of hair and nails. Vitamin B2 is more abundant in animal products, and in particular in organ meats, meat and dairy products.

Similarly, vitamin B9 (folate), is important for the growth and health of the nails by contributing to the formation of red blood cells and the development of new cells. A folate deficiency can cause the pigment in the nails to change, making them stiff and brittle. Vitamin B9 is found in dark green vegetables, citrus fruits, beans, peas, lentils, nuts, seeds and avocados.

• Minerals and trace elements:

Zinc helps stimulate the production of proteins, including keratin and collagen. Zinc is found in seafood, fish, eggs or red meat, while copper is present in wheat, oats or soy.

Iron maintains the strength of the nails , it is essential to ensure optimal growth. An iron deficiency can indeed cause a change in the shape of the nails and their appearance. Meat, fish, eggs and pulses are iron-rich foods.

• Antioxidants:

The antioxidant compounds (vitamin E, vitamin C and flavonoids) present in abundance in fruits and vegetables contain a better resistance of the nails against external aggressions: sun, tobacco, pollution.