The distribution of calcium in fingernails from healthy and malnourished children.

It has previously been observed that nail hardness increases in malnutrition [ 1,2]. In protein-calorie malnutrition this hardness could be due either to an absolute increase in mineral or to a relative increase caused by disturbances in collagen me~bolism, Ieading to a reduction in the onychogen [ 3] . Direct chemical analysis of fingernails has demonstrated an increase in the sodium and calcium concentrations in kwashiorkor [4]. Histochemical analysis of nails from healthy humans has revealed that calcium is concentrated in the dorsal and ventral cells of the nail plate [ 51. In order to determine whether increases in hardness might be due to changes in calcium distribution in nails, clippings from healthy well-nourished, and m~nourish~ subjects, were examined using the electron microprobe X-ray microanalyzer.