Effect of ascorbate deprivation on body weight. Open circles denote control; closed circles denote nitrate-tolerant; open diamonds denote ascorbate-deficient; closed diamonds denote ascorbate-deficient and nitrate-tolerant. Data are mean values±SEM of three guinea pigs per group. *P < 0.05 compared with corresponding standard diet-fed animals. Nitrate tolerance had no significant effect on body weight.