The Influence of the Diet and Energy Intake upon Acute Vitamin B1 Deficiency in the Rat

Abstract

The effectiveness of a diet in producing the neuromuscular symptoms of acute vitamin B₁ deficiency in the young rat varied decidedly with the nature of the non-protein constitutents of the diet, all other components of the diet remaining constant. The most effective diets studied were those in which carbohydrate (sucrose or cornstarch) and fat (coconut fat) each furnished approximately half of the non-protein source of energy. About 90% of the rats on these diets developed neuromuscular symptoms. The method of feeding had less influence than the diet, although the ad libitum method was somewhat more effective than a limited (isocaloric) method in which each rat received 12+ Cal. per day. The time to onset of neuromuscular symptoms was influenced by both the method of feeding and the nature of the non-protein constituents of the diet. The time was greater for the limited than for the ad libitum feeding method. Replacement of one-half of the energy from carbohydrate (sucrose or cornstarch) by that of coconut fat had no effect in the ad libitum feeding but increased the time in the limited feeding procedure. Replacement of cornstarch by dextrinized cornstarch or of three-fourths of the sucrose in the sucrose diet by coconut fat (energy basis) increased the time in both feeding methods; the effect was as great for dextrin as for the coconut fat. The rats on the limited feeding procedure usually attained a lesser maximum weight and the loss from the maximum to the final weight was less rapid and of a lesser degree than for the rats on the ad libitum feeding procedure. Likewise, anorexia was less acute with the limited method of feeding, especially for those diets which were most effective in producing the neuromuscular symptoms. The nature of the non-protein constituents of the diet and, to a lesser degree, the method of feeding, influenced the total energy required for the production of neuromuscular symptoms. The substitution of dextrinized cornstarch for cornstarch in the high starch diet or of coconut fat for about three-fourths of the energy from sucrose in the high sucrose diet more than doubled the energy intake before the onset of neuromuscular symptoms. If the proper diet is used, the incidence of the neuromuscular symptoms of acute vitamin B₁ deficiency is so consistent in young rats that it is suggested that these symptoms constitute the basic criterion of acute vitamin B₁ deficiency in the rat, as well as in the pigeon and the chick.