Brittle or ridged nails: causes and solutions
A nail that splits at the slightest bump, ridges that appear, a crumbling edge… Fragile nails are a very common issue: according to a 2020 dermatological review, they affect up to 20% of the population, particularly women over 50. Good news: in the majority of cases, a few changes in habit make a real difference. Understanding the mechanisms at play—including why the modern diet can deprive your nails of the nutrients they need—is the first step.
At Pure Lab Nutrition, we have relied on a benchmark dermatological review to explain to you what weakens nails and how to strengthen them, from the outside as well as from the inside. You will also find the most frequent mistakes, a sample routine, and the answers to the questions we are asked most often.
📑 Contents
- Recognizing a fragile nail
- Main causes
- Good daily practices
- Frequent mistakes
- The role of nutrition
- Why supplementation is a targeted response
- A sample three-month routine
- When to consult?
- Frequently asked questions
- In summary
Recognizing a fragile nail
Dermatologists describe several signs, often associated:
- Longitudinal ridges: furrows along the length, which can lead to a complete split in the nail
- Splitting: the nail peels off in thin horizontal layers at its tip
- Whitish surface spots: a crumbling surface, often linked to prolonged nail polish use
- Thinning of the nail, which becomes soft and bends easily
Fine longitudinal ridges also appear naturally with age, like wrinkles on the skin. They are not concerning in themselves as long as they are regular, present on several nails, and the nail maintains its usual color.
Main causes
🧽 External causes, the most frequent
- Alternating water and drying: dishes, repeated hand washing
- Chemicals and solvents, including certain polish removers
- Cosmetic treatments: repeated application and removal of polish, gel, or fake nails
- Micro-traumas linked to manual tasks
- Biting or picking at nails
- Very long nails, which lose their moisture more quickly
The alternation between wet and dry nails weakens the cohesion between its cells: "wet-hand" professions (hairdressing, cleaning, care) are particularly affected.
The dermatological review cited as a source also notes a lesser-known trap: wearing waterproof gloves on hands that are still damp keeps moisture in contact with the nail and contributes to weakening it. Hence the importance of drying your hands thoroughly before putting on gloves, and slipping a cotton pair underneath.
🩺 Internal causes
- Natural aging
- Certain skin diseases (psoriasis, lichen, eczema) or a nail fungus
- Certain general disorders: anemia, endocrine disorders, circulatory problems
- Certain medications
- Nutritional deficiencies, particularly in zinc and selenium
The thyroid deserves a special mention: according to the same review, nails are affected in 90% of hypothyroidism cases. Nails that become fragile at the same time as the appearance of fatigue, sensitivity to cold, or unexplained weight gain therefore justify speaking to your doctor.
When no specific cause is found, we speak of "idiopathic" fragile nails.
Good daily practices
- Wear cotton gloves under rubber gloves for dishes and cleaning
- Hydrate nails and cuticles with a cream or oil, right after washing your hands: the 2020 review considers nail moisturizers useful
- Keep nails rather short and file them in one direction only
- Space out polishes and use a gentle remover
- Take breaks between gel or semi-permanent applications
- Avoid using your nails as a tool (opening a can, scraping off a label)
Frequent mistakes
| The mistake | Why it is a problem | What to do instead |
|---|---|---|
| Filing back and forth | Promotes splitting at the tip | File in one direction only, with a fine file |
| Tearing off polish or gel | Removes the superficial layers of the nail | Gentle removal, or at a salon |
| Cutting cuticles to the quick | The cuticle protects the area where the nail forms | Soften and push them back gently |
| Judging a supplement after two weeks | The already-formed nail does not change | Observe the new growth over several months |
| Combining several beauty formulas | Risk of zinc or selenium overdose | Check total doses before any combination |
The role of nutrition
The nail is made of keratin, a protein. A diet sufficiently rich in proteins and micronutrients is therefore the basis: legumes, eggs, fish, meat, dairy products, oilseeds, whole grains.
✅ Nutrients officially recognized for nails
- Zinc contributes to the maintenance of normal nails
- Selenium contributes to the maintenance of normal nails
These are the only two nutrients for which the European Union has authorized a health claim specific to nails (EU Regulation 432/2012). To learn more about the first, read Zinc: roles, daily needs, and signs of deficiency.
💅 What about biotin?
A review published in 2017 in Skin Appendage Disorders (Patel et al.) reports improvements in people suffering from brittle nail syndrome treated with biotin. The authors emphasize, however, that these cases are few and that evidence remains limited. The 2020 dermatological review (Chessa et al.) makes the same observation: vitamins, trace elements, and amino acids have been reported as useful, but in small, poorly controlled studies. We provide a full update in our article Biotin: really effective for hair and nails?
Why supplementation is a targeted response
One might think that eating a few oysters (rich in zinc) or Brazil nuts (rich in selenium) is enough to cover one's needs. In reality, several obstacles make this coverage uncertain on a daily basis:
- Depletion of agricultural soils reduces the zinc and selenium content of vegetables grown in large quantities
- Phytic acid contained in grains and legumes reduces zinc absorption by 30 to 50% according to studies
- Chronic stress increases the body's need for zinc, used by antioxidant enzymes
- Unbalanced or non-varied diets expose one to insufficient intake, often without immediate clinical symptoms
Facing these realities, a supplement combining zinc bisglycinate (a chelated form, better absorbed) and selenium constitutes a targeted and bioavailable response. Zinc bisglycinate, in particular, bypasses competition from phytates.
💡 Our dedicated formula
✅ Biotine Instant+: biotin + zinc bisglycinate + selenium
✅ 1 capsule per day, 30-day course in pocket format
✅ Vegetable capsules, lactose and gluten-free
Zinc and selenium contribute to the maintenance of normal nails; biotin contributes to the maintenance of normal hair and normal skin.
👉 Discover our Biotine Instant+ here.
Patience: a fingernail takes several months to renew itself completely. Results are judged on the new part of the nail that grows, not the old one. To know what to expect, read How long to see the effects of a supplement?
A sample three-month routine
Let's take the example of Claire, who does a lot of dishes and has been wearing semi-permanent polish for years. Here is the simple plan we would suggest for her:
- Weeks 1 to 2: removal of semi-permanent, nails cut short, systematic gloves for household chores
- Every day: hand cream after each wash, oil on cuticles at night, a varied plate with a source of protein at each meal
- The targeted course: daily zinc and selenium (the two nutrients officially recognized for nails), integrated into a fixed ritual (breakfast, for example)
- After three months: comparison of photos taken at the beginning, by looking at the part of the nail close to the cuticle
For an overview, also consult our beauty routine from within for skin, hair, and nails.
When to consult?
Speak to your doctor or a dermatologist if:
- the nails change color or thickness, or peel off
- only one nail is affected, or a dark band appears
- you have other symptoms (significant fatigue, hair loss, skin lesions)
- the situation does not improve despite several months of good practices
Frequently asked questions
❓ I take biotin: should I report it before a blood test?
Yes. The US FDA has reminded that biotin can interfere with certain laboratory tests, including troponin levels. Always report your supplements to your doctor or the laboratory before a blood test.
❓ Can a supplement replace protective measures?
No. If the main cause is external (water, products, polish), no supplement will compensate for repeated aggressions. Both approaches complement each other and are necessary together.
❓ Do little white spots signal a calcium deficiency?
Not necessarily, contrary to a stubborn misconception. Whitish surface plaques can, for example, come from polish worn for months on end, as described by the 2020 review. If the spots spread or the nail changes color or thickness, seek medical advice.
❓ How long does it take before seeing improvement?
A fingernail grows about 3 mm per month. It therefore takes 3 to 4 months to see the base of the nail renew itself. It is on this new growth that you can evaluate the effect of your routine. Consistency is key.
In summary
1️⃣ External causes dominate: water, products, cosmetics
2️⃣ Gloves, hydration, and short nails: the habits that count
3️⃣ Zinc and selenium contribute to the maintenance of normal nails
4️⃣ The modern diet depletes intake: zinc bisglycinate is a targeted and bioavailable response
5️⃣ Several months to judge, and medical advice if the appearance changes
Pure Lab Nutrition ... The art of nourishing your well-being.
Sources:
- Chessa M.A., Iorizzo M., Richert B. et al. (2020). Pathogenesis, Clinical Signs and Treatment Recommendations in Brittle Nails: A Review. Dermatology and Therapy, 10(1), 15-27. Springer
- Patel D.P., Swink S.M., Castelo-Soccio L. (2017). A Review of the Use of Biotin for Hair Loss. Skin Appendage Disorders, 3(3), 166-169. PMC
- TCTMD (2019). FDA Reminds Clinicians About Biotin Interference With Troponin Tests. tctmd.com
- Regulation (EU) No 432/2012 establishing a list of permitted health claims. EUR-Lex
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