Nails: When they are healthy, and what role diet plays?

Have you seen photos of nails infected with fungus? Have you seen green or yellow nails? Or nails with “pits” on their surface?

A healthy nail has a number of characteristics, the most important of which are color, appearance, and steady growth. An extremely important characteristic of a healthy nail is its color. Healthy nails are light pink, while any other color may indicate a fungal infection, injury, specific nutrient deficiencies - which will be discussed below - or disease. Furthermore, the absence of inflammation and pain is another indicator of healthy nails. Inflammation and pain occur, in cases of disease or poor application technique for artificial nails, which can cause detachment and injury to the nail bed. Furthermore, the strength and resilience of nails are another indicator of their health. Healthy nails do not break easily and grow at a steady - though slow - pace. They have a normal thickness, and the nail surface is smooth, without any “dents.” Therefore, healthy nails:

• They are off-white to pink in color.
• They grow at a steady rate.
• They do not break or bend easily.
• Their thickness is normal.
• There are no signs of inflammation (pain, irritation, tenderness) on the nail or in the cuticles (the so-called “skin flaps”).

What can I do to keep my nails healthy?

Nails are made up of proteins, a small amount of lipids, water, and trace elements. To keep our nails in good condition, it’s important to provide them with the essential nutrients they need to grow. However, before we move on to the most useful dietary tips for nail health, let’s look at some practices we should adopt to protect their strength.

• Wear cleaning gloves for daily household chores to protect your nails from constant exposure to chemicals. Contact with chemical detergents can be harmful to your nails and increase their brittleness.
• Keep an eye on your nails. Any change in color, thickness, or growth may be a sign that your nails need extra care or have been infected by a fungus (Pseudomonas aeruginosa infections are quite common and are characterized by a greenish discoloration of the nails).
• Be careful who you trust with the health of your nails! Nail technicians should sterilize their tools and keep their workstation clean before providing you with any service. The most common microorganism found on grooming tools that haven’t been properly and thoroughly cleaned is Staphylococcus aureus, the overgrowth of which can cause acute paronychia. Furthermore, the continuous application of semi-permanent/acrylic/gel without taking regular breaks can weaken the nail. Finally, special attention must also be paid to removal techniques, as poor removal techniques can be harmful to the nail matrix and increase the likelihood of detachment.

What to eat for strong, healthy nails. Essential nutrition tips.

Nail structure. The majority of the nail (80–90%) consists of hard keratin, epithelial keratin, water, stearic and glycolic acids, as well as a variety of minerals, such as calcium, copper, sodium, and zinc. The nail’s durable structure is due to its adequate hydration, which ranges from 16–24%, as well as to the disulfide bonds that connect the keratin protein fibers to one another. To keep our nails healthy and strong, it is important to focus on the following nutrients (see table below).

Adequate protein. The nail is a compact protein structure, consisting of keratin protein molecules, linked by sulfur-containing compounds, which are responsible for its stability. Therefore, to support this compact structure, it is important to consume an adequate amount of complete protein and to prioritize sources rich in cysteine, an amino acid found in high concentrations in the nail’s primary structural protein, keratin. Good sources of protein include meat, fish, yogurt, cheese, nuts, and legumes. Protein deficiencies are rare in the general population and may occur in cases of malnutrition or undernourishment, with nails exhibiting fewer layers and a greater tendency to break.

Proper hydration. As mentioned above, hydration levels of 16–24% help reduce nail brittleness by improving the stability of the nail structure. The general recommendation is 1 mL per 1 kcal, meaning that 2,500 calories correspond to 2,500 mL/2.5 L of water. Always keep a bottle of water nearby and drink, even when you’re not thirsty, while also increasing your intake of fruits and vegetables, which are highly hydrating foods. Dehydrated nails lose their natural shine, resulting in a dull appearance and often “flaking.”

Omega-3 fatty acids. Omega-3 fatty acids come into play here as well, with insufficient intake of omega-3s contributing to dryness and reduced hydration in the nail area. The partial fat content of the nail structure, along with water, are key components for hydration and maintaining its hardness. Rich sources of omega-3 fatty acids include walnuts, fatty fish, and flaxseed.

Iron. One of the most important minerals for maintaining healthy nails is iron. Essential for normal blood formation - in conjunction with vitamins B2, B6, B9, and B12 - it contributes to proper blood supply and the transport of oxygen and nutrients to the nail matrix, supporting its normal growth. Reduced iron intake or long-term low ferritin levels can affect the nail’s growth rate as well as its color due to abnormal blood supply, while another characteristic symptom of low ferritin is koilonychia, with the characteristic spoon-shaped nail, featuring vertical ridges. Rich sources of iron include red meat, fish, legumes, tahini, and certain dried fruits.

High-quality carbohydrates. Normal nail growth depends on the proper management and supply of the nutrients needed to support it. Without an immediate supply of energy from food, the utilization of nutrients becomes impossible. Sources of carbohydrates, such as whole grains, fruits, and legumes, help provide the necessary glucose energy substrates for normal nail growth and the maintenance of its shine and attractive appearance.

What about dietary supplements?

Before we wrap up our article on dietary supplements you can try, if you notice a change in the appearance or color of your nails, it’s important to identify which change is and consult a dermatologist to determine whether the symptom you’re experiencing could be due to a nutrient deficiency, improper removal technique, a fungal infection, or a combination of these, so you can obtain the appropriate supplement.

Biotin. Biotin, or vitamin B7, belongs to the B-complex vitamins and is one of the most important vitamins for the bonding of keratinocytes into keratin structures, such as hair and nails. Biotin deficiency has been associated with increased brittleness and poor nail quality, while doses of 2.5–10 mg for a short period of a few months are considered well-tolerated.

Zinc. Zinc is one of the most important minerals, used for the normal synthesis of proteins, and thus keratin. If distinct white spots are visible, it is either likely that the nail has been injured, or there may be a potential zinc deficiency. Chelated or picolinate zinc supplements, which are more absorbed, contribute to more effective repair of the nail plate in case of injury and to faster healing.

Verisol collagen peptides. In a previous article, we discussed in detail the benefits of taking Verisol collagen peptides as a supplement. Holland & Barrett’s expert formulation of collagen peptides, when tested on a small group of volunteers, improved the appearance and strength of nails while increasing their length by 2.7 mm per month after 12 weeks of consistent use.

Omega-3 fatty acids. Supplementing with omega-3 fatty acids helps reduce inflammation and maintain hydration in dehydrated nails or nails that have been injured or infected by microorganisms.

Vitamin D. Low levels of vitamin D may affect the appearance and color of the nail, and can exacerbate existing inflammation in nails that are already injured or prone to breaking. Monitor your serum vitamin D levels regularly, as a deficiency has been linked to a variety of symptoms throughout the body.

Silica. Silica is a trace element that provides strength to solid structures, such as bones and nails. There is a small number of studies supporting the use of silica supplements for brittle nails, as it appears to improve nail strength; however, the data so far is limited, and more studies in humans need to be conducted.

In conclusion

Nails are another indicator of our overall health and require proper nutritional care, as well as the right specialists to remain strong and healthy. Proper cleaning and care, along with adequate intake of essential nutrients such as protein, water, omega-3 fatty acids, complex carbohydrates, biotin, iron, and zinc, is the perfect combination for maintaining nail growth and resilience.

Scientific References

Chessa, M. A., Iorizzo, M., Richert, B., López-Estebaranz, J. L., Rigopoulos, D., Tosti, A., ... & Piraccini, B. M. (2020). Pathogenesis, clinical signs and treatment recommendations in brittle nails: a review. Dermatology and therapy, 10(1), 15-27.

Reinecke, J. K., & Hinshaw, M. A. (2020). Nail health in women. International Journal of Women's Dermatology, 6(2), 73-79.

Scheinfeld, N., Dahdah, M. J., & Scher, R. (2007). Vitamins and minerals: their role in nail health and disease. Journal of drugs in dermatology: JDD, 6(8), 782-787.

Seshadri, D., & De, D. (2012). Nails in nutritional deficiencies. Indian Journal of Dermatology, Venereology and Leprology, 78, 237.

Zaraa, I., & Richert, B. (2025). Nail Supplements: When, How, and Why?. Skin Appendage Disorders, 11(2), 176-181.