Human Daily Requirements of Dietary Ascorbic Acid

Abstract

EARLIER investigations¹ on insane, but physically healthy, experimental subjects, who have been forcibly tube-fed owing to their refusal to take nourishment, have established certain relations between the protective dose of an antiscorbutic required by man and the protective dose of the same antiscorbutic required by a guinea pig, on the view that the degree of susceptibility to microscopic scorbutic alterations in the teeth in guinea pigs and the prescorbutic reduction in the strength of the cutaneous capillaries in man are approximately the same. On the basis of this result, further experiment showed that, in order barely to protect himself against the earliest onset of a shortage of vitamin C, an adult weighing 60 kgm. requires a daily dose of an anti scorbutic (fresh orange juice) fourteen to twenty times as large as a guinea pig weighing one third of a kilogram requires barely to protect itself against scorbutic alterations in the teeth which can be determined microscopically. In a further investigation, these facts have been utilised to establish indirectly man's daily requirements of ascorbic acid by means of experiments on guinea pigs.