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One of the most common causes of brittle nails is nutritional deficiency. Doctors explain that low levels of iron, biotin, zinc, or protein may affect nail strength and growth. Iron deficiency, in particular, is often linked to weak, thin, or spoon-shaped nails. Because nails are made largely from keratin — a type of protein — inadequate protein intake may also contribute to fragile nails that crack easily.
Biotin, also known as vitamin B7, is another nutrient commonly associated with nail health. Some studies suggest biotin may help strengthen weak nails and reduce splitting. Foods rich in biotin include eggs, nuts, seeds, fish, and whole grains. However, experts stress that supplements should only be taken responsibly and ideally after medical advice.
Dehydration may also affect nail condition. People who frequently expose their hands to water, cleaning products, or strong detergents may notice nails becoming dry and fragile over time. Using moisturizing creams and wearing gloves during cleaning can help protect nails from damage.
