Acute effects of a zinc supplement taken before a glucose load

Observations from animal studies suggest that individuals who consume oral zinc supplements may show elevations in blood glucose. To examine whether this effect occurs in humans, we conducted glucose and zinc tolerance tests on eight adult women volunteers. All eight volunteers were subjected to two test conditions: (a) ingestion of 50 g D-glucose and (b) ingestion of 110 mg ZnSO4.7H2O followed 60 minutes later by ingestion of 50 g D-glucose. Two subjects also ingested 110 mg ZnSO4.7H20 without glucose. Blood samples were drawn before and 15, 30, 45, 60, 90 and 120 minutes following consumption of the glucose solutions, and were analyzed for glucose and zinc content. Our results did not indicate significantly altered glucose tolerance in response to the acute elevation of plasma zinc. These preliminary data suggest that increasing plasma zinc prior to elevating blood glucose does not alter the rate of glucose removal from circulation or the area under the glucose curve in normal individuals.