Intestinal and renal loss of infused minerals in patients with severe short bowel syndrome.

Intestinal and renal loss of infused calcium, magnesium, and zinc were studied in eight patients on permanent partial parenteral nutrition because of extensive bowel resection by comparing two 4-day infusion periods, one with Ca/Mg/Zn supplied (B) and one without (A). Dietary intake and parenteral supply of other nutrients were constant. In period B the daily supply of 9 to 11.3 mmol Ca, 10 mmol Mg, and 70 to 200 mumol Zn was infused over a 4-h period during which S-Ca increased by 8%, S-Mg by 37%, and S-Zn by 60%. During Ca/Mg/Zn infusion renal Ca excretion increased with 81% of the amount of Ca infused. Mg loss with 63% of infused Mg, and Zn loss with 8% of infused Zn. Increased fecal loss of Ca and Mg occurred in patients with functioning colon, but not in patients with jejunostomy. Fecal Zn increased in both groups. Increased fecal Ca presumably reflected impaired absorption of dietary Ca, since endogenous fecal Ca loss was unchanged. The kidneys represented main excretory route for infused Ca and Mg and the gastrointestinal tract was the main excretory route for infused Zn. The majority of patients had a net retention of infused Ca (16%), Mg (27%), and Zn (61%).