Mineral balance during nutritional supplementation in adolescents with Crohn disease and growth failure.

The adaptive response of whole body mineral metabolism and collagen turnover to nutritional supplementation was determined in adolescent males with Crohn disease and growth failure. Body calcium, magnesium, phosphorus, and nitrogen status was characterized in six patients before and after 3 weeks of nutritional supplementation and in five healthy age- and sex-matched controls by the metabolic balance technique; collagen turnover was assessed by urinary hydroxyproline excretion. Fecal calcium (P less than 0.05), magnesium (P less than 0.01), and nitrogen (P less than 0.01) losses were significantly greater in the Crohn disease patients compared with the controls; after dietary supplementation, only fecal magnesium excretion increased further (P less than 0.001). Approximately twofold increases in phosphorus (P less than 0.001), nitrogen (P less than 0.02), and calcium (P less than 0.05) retention occurred with nutritional supplementation, whereas the marked renal conservation of phosphorus (P less than 0.001) suggested that this mineral was a limiting nutrient. Urinary hydroxyproline excretion was reduced (P less than 0.05) compared with the control values; however, with nutritional supplementation, urinary hydroxyproline excretion increased significantly (P less than 0.02), suggesting that the soluble fraction of tissue collagen was rapidly turning over during nutritional rehabilitation. These findings suggest that the mineral deficiencies present in adolescents with Crohn disease and growth failure can be reversed with nutritional supplementation. Furthermore, the improvement in nutritional status is reflected in the restoration of collagen-containing tissues of the body. However, nutrient imbalances may be present during nutritional therapy, thereby preventing optimal recovery from malnutrition.