EXPERIMENTAL STUDIES ON MAN WITH A RESTRICTED INTAKE OF THE B VITAMINS

Abstract

Part I. Following several months of dietary and test standardization 8 normal young men were maintained at constant wt. on 3300 Cal. daily with 0.185 mg. thiamine, 0.287 mg. riboflavin and 3.71 mg. niacin per 1000 Cal. Other dietary elements were constant and adequate. All [male][male] received daily capsules which were blanks for 4 of the [male][male] and provided adequate B vits. for the other 4. The 24-hr. urinary thiamine became constant in a mo., averaging 7 and 114 [gamma] in the 2 groups, respectively. The 24-hr, urinary riboflavin became constant in 2 mos., averaging 137 and 438 [gamma], in the 2 groups, respectively. There were no differential changes in: cardiovascular responses to brief or to prolonged work, "fitness" test scores, strength and psychomotor functions, heart size and E.C.G., gastric emptying, basal metabolism, blood lactate in rest, after work and after glucose, sensory and intellective functions, and objective aspects of personality. Detailed clinical examinations were also negative. There was a slight but statistically significant tendency for blood pyruvate to rise in the [male][male] receiving only blank capsules. Part II. Immediately on the conclusion of the expt. reported in Part I, these [male][male] went on a diet substantially devoid of B vits., daily capsules being ingested as before to provide controls. Activity was set at 4000 Cal. daily. The control subjects maintained satisfactory constancy in all tests, sensations and functions. Anorexia, and later nausea and increasingly frequent vomiting, began in about a wk. in the [male][male] previously on a. restricted intake of B vits. The [male][male] previously receiving a good intake of B vits. showed a similar course with a lag of about 5 or 6 days. Because of rapidly progressing debility thiamine supplementation was started after 22 days. This alone, with no other changes, produced dramatic and progressive improvement for the final 10 days of the expt. The test results showed that the methods used were sensitive and consistent, and a detailed quantitative description of the effects of very acute deficiency was obtained. The order of appearance of deterioration in function and performance was: first[long dash]gastrointestinal, second[long dash]emotional and "fitness," third[long dash]metabolic, neurologic and cardiovascular, fourth[long dash]strength, intellective functions, special senses.