Table 1a.

Gender-specific serum concentrations (ppb) of essential trace elements in children of the Kahemba District, Democratic Republic of Congo.

Essential elements Fe, Se, Cu, and Zn are found in serum at concentrations that do not differ between boys and the girls.

Elements	Males (N = 107)	Females (N= 88)	* P values
Fe
Mean (SD)	1275.49 (885.60)	1127.05 (795.37)	0.22
Median (IQR)	1038.63 (810.33 – 14.91.42)	916.79 (600.87 – 1442.00)
Se
Mean (SD)	31.21 (21.33)	27.89 (18.87)	0.25
Median(IQR)	24.96 (16.12 – 39.02)	24.20 (15.10 – 34.92)
Cu
Mean (SD)	1051.98 (458.65)	978.01 (384.08)	0.22
Median (IQR)	949.34 (714.95 – 1295.13)	909.38 (731.69 – 1197.48)
Zn
Mean (SD)	701.37 (284.80)	678.73 (245.17)	0.55
Median (IQR)	665.21 (474.86 – 899.57)	652.55 (490.82 – 843.44)

N = number of subjects; SD = standard deviation; IQR = Inter quartile range;

^*P-value based on t-test for the comparison of means.