A recent report of Keys and his associates1 recounts their observations in an extensive investigation of the influence of a borderline deficiency and of an acute deprivation of some of the B group of vitamins in human subjects. Eight normal young men were given a diet providing a daily allowance of 3,300 calories, 75 Gm. of protein and 0.18 mg. of thiamine, 0.25 mg. of riboflavin, 3.5 mg. of niacin per thousand calories, with 5,000 units of vitamin A and adequate vitamin D. Four were given in addition 1 mg. of thiamine, 1 mg. of riboflavin and 10 mg. of nicotinic acid amide; these served as the supplemented control group. The experiment extended over one hundred and sixty-one days.
The urinary excretion of thiamine in both groups declined rapidly and in less than thirty days reached a more or less constant level. At the end of the study 1.1