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Complete Guide to Nail Care

Complete Guide to Nail Care

Published: 4 December, 2023 | 7'

Morphology, Composition and Functions of Nails

Nails are located at the end of the fingers (distal phalanx) and are surrounded by ligaments and tendons, which help anchor them to the underlying bone and are essential for their mechanical functions. The nail unit (or nail complex) consists of a nail plate, four specialized epithelia (the proximal fold, matrix, bed, and hyponychium - which is located under the free edge of the nail and seals the distal edge -) and lateral folds (including the cuticle).

Nails are characterized by their shiny, smooth appearance, uniform consistency, and a certain flexibility in their structure. The visible nail bed is pink and the free margin is white, with a slight curve in the view of the free margin.

Nail Composition

  • Nails contain organic elements (e.g. proteins) and inorganic elements (e.g. calcium). Among the latter, the nail plate is rich in calcium, which exists in the form of phosphate in hydroxyapatite crystals.
  • Carbon, nitrogen, and sulfur are the organic elements found in the nail plate. Sulfur is a constituent of the amino acid cystine and is responsible for the hardness of the nail plate.
  • The lipid content of the nails is less than 5% and is mainly in the form of cholesterol, and their levels are regulated by hormones. The phospholipids contained in the nails contribute to their flexibility.
  • The nail is also composed of keratins, with 80% being the so-called "hard" keratin and 20% being epidermal keratins. Hard keratins are responsible for the roughness and resistance of the nail, as they contain a large number of sulfur-containing amino acids such as cystine, glutamic acid, and serine.

Nail Functions

  • They act as protective covers for the fingertips of the hands and feet.
  • They enhance tactile discrimination of the hands and allow for precision and delicacy in finger functions.
  • The nails of the feet contribute to their biomechanics.
  • They are used for scratching, in addition to various aesthetic functions.

Growth and Renewal of Nails

nail growth

Nails grow continuously throughout life, and their growth rate depends on various physiological, environmental, and pathological conditions. The growth rate of the nail relates to both the longitudinal elongation of the nail plate and its thickness.

The growth rate of nails reaches its maximum between the ages of 10 and 14, and from the second decade onward, it begins a steady decline with age. In adults, the nails on the hands grow approximately 0.1 mm per day, with an average growth rate of 3.5 mm per month. The growth of toenails is 0.03 mm per day (about one-third compared to fingernails).

The regeneration time of nails is between 100 and 180 days (6 months) for the hands, while for the feet, it is 12-18 months. When nails have any functional disorders, it has a direct negative effect on their growth.

Common Nail Problems

Nail abnormalities can include configuration, surface alterations, consistency modifications, and soft tissue anomalies. Let's look at the most common ones.

Yellow Nails: Causes and Solutions

Nails show yellowish to green-gray discoloration, and in some cases, loss of the cuticle, thickening, and hardening occurs. Additionally, nail growth significantly decreases. The causes can be due to aggressive nail polishes or products, and the habit of smoking.

General recommendations are:

  • Thoroughly clean the nails and use specific bleaching products containing chlorine-based ingredients, followed by adequate hydration.
  • The use of vitamin E is recommended, as well as intense hydration.
  • Do not use nail polish remover on the nails more than once a week, preferably without acetone.
  • Always wear clean socks and frequently expose your feet to fresh air.

Ridged Nails: Causes and Improvements

Ridges on the nails, both vertical and horizontal, are lines that feel raised when you rub your fingers across their surface. Sometimes, ridged nails are accompanied by brittle nails that may slightly split at the ends, and they are usually thinner and more prone to breaking than nails without pronounced ridges.

The causes may be associated with aging or with the essential components for strong nails. Other causes include excessive biting or picking of nails, exposure to chemicals, and excessive moisture (e.g. hairstylists or housekeepers), frequent use of nail polish remover, among others.

Some recommended measures to counteract this situation are:

  • Use moisturizing products on the hands and nails, such as creams that contain vitamin E or vegetable oils.
  • Avoid soaking or exposing the nails to water or cleaning chemicals for an excessive period of time.
  • Use protective gloves when using cleaning products or washing dishes.
  • Use nail remineralizers and let the nails "rest" from harsh nail polishes and polish removers.
  • In addition to a balanced diet, consume supplements that contain biotin, sulfur-containing amino acids, among others.

Peeling Nails: Causes and Solutions

Peeling or splitting nails have a very dry appearance, and the different layers that make up the nail plate peel off or "flake" away. Trauma, prolonged exposure to water or other conditions, excessive use of nails as tools, picking or peeling off nail polish, and the application of artificial or acrylic nails can cause peeling.

Recommendations to prevent peeling or flaking nails:

  • If you use artificial nails, it is important to carefully remove all nail coverings without scraping or pulling.
  • Protect the nails by applying a clear nail polish.
  • File the nails around the tips, in a curving direction.
  • If you buff the nails, do so in one direction only.
  • Use moisturizers daily, and more frequently if you frequently expose your nails to water.
  • Do not use nails as tools to pick up or open objects, as it can weaken them.
  • It is recommended to incorporate iron and biotin into the diet or supplement it with nutritional supplements.

Soft or Brittle Nails: Causes and Strengthening

Brittle nails are characterized by increased fragility of the nail plate, resulting in dryness, fissures, peeling, and vulnerability to breaking or splitting. It is a fairly common condition that can affect up to 20% of the population, with women being affected twice as often as men.

The most common causes include aging, occupational trauma, exposure to chemicals, and filing the nail surface. General recommendations to prevent or improve this condition are:

  • Use moisturizing creams, ointments, or oils on the hands and nails.
  • Use gloves to avoid contact with irritating agents and avoid filing the nail surface.
  • Incorporate foods into your diet that contain good levels of biotin, iron, zinc, keratin, L-methionine, L-cystine, and vitamin B group. You can also complement your diet with nutritional supplements that provide these ingredients.

General Tips for Nail Care

  • Continuously moisturize your hands and feet, especially after washing them or before going to bed. When applying moisturizer, make sure to rub it around and directly onto the nails.
  • Drink plenty of water every day, as nails tend to have around 18% water content. Dehydration can cause nails to break easily.
  • Consume a variety of foods that include fruits, vegetables, green leafy vegetables, and lean proteins, which help nourish and hydrate the nails. You can also complement your diet with nutritional supplements.
  • Avoid biting nails and cuticles. It is recommended not to cut cuticles, but rather push them back using the appropriate tool, avoiding direct contact with the nail.
  • Buff and file the nails in the same direction as they grow.
  • Avoid placing sharp objects under the nails, as they can break the hyponychium and affect the nail seal or protective barrier.
  • Keep the nails short, straight, and rounded to minimize the nail surface area.
  • As for manicure treatments, it is advisable to space them out, apply a nail hardener, and avoid using acetone-based polish removers.
  • You can use vegetable oils and warm paraffin baths to provide extra hydration and softness to your hands.
  • Reduce hands' exposure to water and use mild soaps.
  • Protect your nails by wearing gloves when coming into contact with chemicals.

MARNYS Products for Natural Nail Care

Hydration and nutritional support are fundamental factors for the well-being of nails, requirements that can be provided by the ingredients contained in Marnys products. Let's see which ones are recommended for nail beauty and well-being.

Oils for Nail Care

  • Jojoba Oil: Its unique composition of ceramides and tocopherols (vitamin E) makes it an ideal moisturizer and regenerator for nails.
  • Coconut Oil: It is an extraordinary emollient that restores hydration without leaving a greasy feeling. It also improves firmness and prevents nail breakage.
  • Argan Oil: It provides omega fatty acids and a large amount of vitamin E, which promote the structure and moisturization of the nail, as well as protect it with its antioxidant capacity.
  • Shea Butter, Argan, Rosehip, and Calendula: The combination of shea butter with argan and rosehip oils multiplies their emollient, antioxidant, and restorative properties for the nail structure.

Nutraceuticals. Skin, Hair, and Nails

  • Vitamins and Minerals: We have a very complete line of vitamins and minerals such as Vitahelp, which can promote nutritional support for nails.
  • Beauty In & Out Elixir and Capsules: These two products provide, in convenient and easy-to-ingest formats, the ingredients that are part of the normal nail structure, such as vitamin B group, sulfur-containing amino acids (L-cystine), omegas, minerals such as iron and zinc, as well as antioxidants like vitamins C and E.


Nail care is essential to keep them healthy and beautiful. With the advice provided in this article, you can improve the appearance and strength of your nails. Remember to follow a regular care and nutrition routine to achieve better results. Enjoy healthy and radiant nails!


Content written and reviewed by specialists from the MARNYS Scientific Information area. This article is informative and does not replace the consultation of a specialist.