On the Prophylactic Action of Vitamin A in Helminthiasis

Abstract

(1) Experiments have been conducted to investigate the part played by Vitamin A in the prophylaxis of helminthiasis.Heterakis gallinæin the chicken andParascaris equorumin albino rats were used.(2) The evidence tends to show that in Heterakis infestation the vitamin content of the diet has no effect on the course of the infestation. In Ascariasis in rats, however, the vitamin affects significantly the hatching, survival and rate of development of the larvae within the host.(3) The writer can put forward no reason for this difference except to suggest that it may lie in. the life history of the parasites. Considering her own results and those of previous workers as cited in the introductory part of this paper, it seems obvious that the vitamin is effective in cases where the parasite comes into close contact with the host tissues.(4) Some notes on the viability of eggs are added.