Apparent copper absorption from a vegetarian diet

Background: Vegetarian diets often contain more copper than do nonvegetaria n diets, but observations of decreased plasma copper associated with vegeta rian diets suggest that these diets have lower copper bioavailability than do nonvegetarian diets. Objective: Our objective was to determine apparent copper absorption from c ontrolled lactoovovegetarian and nonvegetarian diets. Design: Eighteen women aged 20-43 y consumed lactoovovegetarian and nonvege tarian weighed diets for 8 wk each in a randomized, crossover design. The l actoovovegetarian and nonvegetarian diets provided 1.45 and 0.94 mg Cu, 38 and 16 dietary fiber, and 1584 and 518 mg phytic acid, respectively, per 9. 2 MJ (2200 kcal). After the women had been consuming each diet for 4 wk, th eir apparent copper absorption was determined by measuring the fecal excret ion of the Cu-65 stable isotope, extrinsically added to the entire menu as (CuCl2)-Cu-65. Results: Plasma copper and ceruloplasmin were not affected by diet. The eff iciency of apparent copper absorption from the lactoovovegetarian diet was less (33%) than that from the nonvegetarian diet (42%) (pooled SD: 9%; P < 0.05). However, because the lactoovovegetarian diet contained approximate t o 50% more copper, the total apparent copper absorption from the lactoovove getarian diet (0.48 mg/d) was greater than that from the nonvegetarian diet (0.40 mg/d) (pooled SD: 0.09 mg; P < 0.05). Conclusion: Although copper was less efficiently absorbed from a vegetarian diet than from a nonvegetarian diet, total apparent copper absorption was greater from the vegetarian diet because of its greater copper content.