Human nails and body iron.

The iron content of human nails has been measured by atomic absorption spectrophotometry and compared with other measurements of iron status including the bone marrow. Four groups of individuals were studied: 40 healthy laboratory staff, five iron-deficient subjects before and during iron therapy, four patients at various stages of treatment with iron, and 15 postmortem cases. The iron status of the individual was reflected by the amount of iron present in nail samples. Nail sampling is proposed as a cheap, noninvasive method of assessing the iron status of the individual.