From the Guidelines
Vitamin deficiencies that can negatively impact nail health include biotin, vitamin C, iron, zinc, and vitamin A deficiencies, which can cause a range of nail problems, including brittle nails, hangnails, and slow growth. To improve nail health, it is essential to consume a balanced diet rich in these nutrients or consider supplements if needed.
- Biotin deficiency can cause brittle nails with ridges, and supplementation has been successful in treating brittle nails (onychoschisis) 1.
- Vitamin C deficiency can lead to hangnails and slow growth, while iron deficiency can cause spoon-shaped nails (koilonychia).
- Zinc deficiency can result in white spots and slow growth, and vitamin A deficiency can make nails brittle and prone to breaking.
- Protein deficiency can also cause nail problems like ridges and slow growth. Foods beneficial for nail health include eggs, nuts, leafy greens, citrus fruits, lean meats, and dairy products, as listed in the table of physiological effects and sources of vitamins 1. These nutrients support nail growth by providing the building blocks for keratin production and supporting the cellular processes necessary for healthy nail formation. Visible nail improvements typically take 3-6 months as nails grow slowly, replacing themselves completely over this period. Biotin supplements typically range from 2,500-5,000 mcg daily, and a balanced diet that includes a variety of whole foods can help support nail health.
From the Research
Vitamin Deficiencies Affecting Nails
- Biotin deficiency can lead to brittle nail syndrome, which can be treated with a 2.5-mg dose of biotin daily 2
- Silicon deficiency can also cause brittle nail syndrome, and supplementation with a 10-mg dose of silicon daily can be beneficial 2
- Other micronutrient deficiencies, such as vitamin B12, vitamin C, zinc, iron, copper, and selenium, may also affect nail health, but there is no evidence to support their use in improving nail health in well-nourished patients 2, 3
- Vitamin deficiencies can lead to cutaneous abnormalities, including nail changes, and these manifestations can provide clues to the underlying deficiency 3
- Micronutrients such as B vitamins, vitamin C, and minerals like zinc, iron, and selenium play essential roles in basic metabolic pathways and can affect energy, fatigue, and cognition, which may indirectly impact nail health 4