Dietary requirements of subjects exposed to hyperbaric He-O2 conditions: effects of various levels of vitamin supplementation.

A 24-d growth study was conducted on rats exposed to ambient air, 11 ATA He-O2, or 21 ATA He-O2 conditions. The rats were fed either a standard diet or the standard diet supplemented with 25, 50, or 100% increase of all vitamins, or the last with an additional 50 or 100% increase of casein. Fat, as cod liver oil was increased 0.5, 1.0, or 2.0% of the diet as the vitamins were increased. The vitamin and fat-supplemented diets, with or without supplemental casein, were adequate to support normal growth of the rats exposed to 11 ATA but not 21 ATA He-O2 conditions. Urine excretion and water consumption were closely related and varied in accordance with the adequacy of the diet. Feed digestibility was not a limiting factor in determining the growth of the rats under the three environments. The composition of the rat carcasses varied minimally.