Randomized study of zinc supplementation during pregnancy

The hypothesis underlying this study was that a daily dietary Zn supplement during pregnancy would be associated with higher values for selected indices of Zn nutriture than corresponding values for non-Zn-supplemented subjects, if, and only if, Zn status of the unsupplemented control group was sub-optimal. The 12 test and 17 control subjects were healthy, apparently well-nourished anglos who were enrolled before the 12th week of gestation. Mean age=29 yrs, mean parity=0.8. Test subjects received a daily supplement of 15 mg Zn (mean compliance=90%) from the time of enrollment until 3 months post-partum. The supplement was taken at bedtime while other vitamin/mineral preparations were taken before breakfast. Blood samples were obtained at 4 week intervals from enrollment. Selected preliminary results: plasma Zn declined progressively with length of gestation to a nadir of 53 +/- 6 ..mu..g/dl at 10 months. (Non-pregnant mean 77 +/- 7). As in a previous, non-randomized, study the rate of decline for the test group did not differ from that of the control group. Mean monthly neutrophil Zn ranged from 43 +/- 8 - 50 +/- 14 ..mu..g/10/sup 10/ cells; there was not consistent pattern across gestation. Serum alkaline phosphatase activity and pre-albumin of the test group did more » not differ from the control group. These data did not give any indication of sub-optimal Zn nutriture in this pregnant population. « less