Table 1.

General characteristics of Zinc and Placebo groups

Variables		Zinc group (n = 21) n (%)	Placebo group (n = 17) n (%)
Gender	Female	20(95%)	14(82%)
	Male	1(5%)	3(18%)
Education Level	Elementary school	3(14%)	5(29%)
	Secondary school	8(38%)	2(12%)
	High school	7(34%)	5(29.5%)
	Academic	3(14%)	5(29.5%)
Smoking	No	18(86%)	15(88%)
	Yes	3(14%)	2(12%)
Marital Status	Single	2(9.50%)	2(12%)
	Married	19(90.50%)	15(88%)
Income	Less than 200 thousand	2(9%)	1(6%)
	200 to 400 thousand	6(29%)	2(12%)
	400 to 600 thousand	7(33%)	10(59%)
	More than 600 thousand	6(29%)	4(23%)