Interaction of Dietary Carbohydrate, Ascorbic Acid and Copper with the Development of Copper Deficiency in Rats

Abstract

The effects of dietary carbohydrate and ascorbic acid on the development of copper deficiency were investigated. Male Sprague-Dawley rats (n = 48) were fed one of eight diets in a 2 × 2 × 2 factorial design for 21 d. These diets varied in copper (1.11 or 8.96 µg Cu/g diet), carbohydrate (sucrose or cornstarch, 62.3%) and ascorbic acid (0 or 1%). Compared to controls, copper-deficient rats had lower hematocrit and ceruloplasmin levels, lower levels of copper and iron in several tissues, higher heart weights and lower spleen weights. During copper deficiency, liver iron levels were higher than control levels when cornstarch, but not sucrose, was the carbohydrate source, while liver and gastrointestinal tract weights were higher with sucrose compared to cornstarch. Copper-deficient rats fed ascorbic acid had significantly (P < 0.05) lower hematocrits when fed sucrose compared to starch [29.6 ± 1.2 vs. 36.8 ± 1.2 g/dl (mean ± SEM), respectively]. In copper-deficient rats, sucrose tended to lower the apparent absorption of copper compared to cornstarch, while ascorbic acid reduced the apparent absorption of iron. Thus, sucrose and ascorbic acid appeared to reduce hematocrit levels through effects on mineral absorption.