The Effect of VITAMIN SUPPLEMENTATION on SOLDIERS Residing in a COLD ENVIRONMENT: PART 1. PHYSICAL PERFORMANCE AND RESPONSE TO COLD EXPOSURE

Abstract

During the period January 2, 1953 to March 10, 1953, an experiment to study the effect of vitamin supplementation on physical performance while residing in a cold climate was performed at Pole Mountain, Wyo. (8300 ft. elevation), utilizing 86 military personnel as test subjects. The test subjects were randomly divided into two groups. The control group (42 men) received a capsule containing 6 mg. of ascorbic acid 4 times a day. The supplemented group (44 men) received 4 times a day capsules identical in size and appearance, except for the color, and these contained 10 mg. thiamine, 10 mg. riboflavin, 100 mg. niacinamide, 80 mg. calcium pantothenate, 40 mg. pyridoxine, 2.5 mg. folic acid, 300 mg. ascorbic acid, and 4 μg. of vitamin B12 per capsule. The subjects were maintained on a program of high physical activity, mostly out-of-doors, throughout the test. During the period of the test the average daytime weather conditions were as follows: temperature 26° F., wind velocity 13 mph, windchill 1030 Kg. cal./sq.m./hr. The clothing worn during the outdoor activities was prescribed and was restricted to less than the amount required for comfort when inactive under tile prevailing weather conditions. During the first six weeks of the test, 4100 calories were offered in the diet, and a mean of 3500 calories was consumed. During the last three weeks, 2250 calories were offered in the diet, and essentially all of this was consumed. Physical performance was measured at approximately weekly intervals, using the Harvard step test, Army physical fitness test, hand dynamometer and a standardized forced march technique. A contest march was performed once during the seventh week of the test. In the Harvard step test and the Army physical fitness test, the performance of both groups continued to improve throughout the 10 weeks of study, including the 3-week period of caloric restriction. There was no statistically significant difference between the two groups in the degree of improvement of performance. Likewise, in the hand dynamometer tests, the forced marches, and contest march there were no statistically significant differences in performance between the two groups. During the last three weeks of the experiment a study was made of the fall in rectal temperature during exposure to cold while at rest. Three such tests were conducted out-of-doors, one indoors. In all instances the supplemented group showed a lesser fall in rectal temperature, and the difference between the two groups was statistically significant. A caloric deficit of 1200 calories per day for 22 days did not lead to detectable impairment of physical performance.