Recently two of us reported on the treatment of the brittle nail with gelatin.1 This study raised several questions requiring further investigation. Among these were the following: (1) the duration of the effect after ingestion of gelatin has been stopped; (2) which clinical conditions and pathological states of the nails respond to gelatin intake; (3) the mechanism of the effect of gelatin on nails.
It was felt also that an attempt should be made to correlate other physiological changes in pathological nails. Specifically, the concept that blood levels of calcium, phosphorus, and/or the basal metabolic rate in pathological nails are disturbed, was challenged. This idea seems to have established itself firmly on the medical mind, in spite of the work of Kile2 and others. A recent query on brittleness in nails was answered by giving calcium deficiency3 as the usual cause.
ROSENBERG S, OSTER KA, KALLOS A, BURROUGHS W. Further Studies in the Use of Gelatin in the Treatment of Brittle Nails. AMA Arch Derm. 1957;76(3):330–335. doi:10.1001/archderm.1957.01550210054006