Moderate evidencemineral
Iron for Brittle Nails
Iron is essential for hemoglobin production and oxygen delivery to nail matrix cells. Iron deficiency causes nail bed hypoxia, resulting in thin, concave (koilonychia), and brittle nails due to impaired keratin synthesis.
How strong is the research?
Moderate evidence
Based on cohort study data — strong observational evidence.
Research source
SourceCashman MW et al. · Cutis 2010How much to take
18–36 mg
Iron deficiency is a common cause of koilonychia (spoon nails) and nail brittleness. Test ferritin levels.
When to take it
Best taken: empty stomach