Table 1.

Studies that examined the effect of sex, menopause, pregnancy, and age on blood Mn concentration.

Variables	No. (n)	Study subjects and findings
Sex	(n = 2005)	Korean general population 20 y or more; KNHANES 2008/GM of blood Mn in female vs. male: 1.403 vs. 1.192 μg/dL* [19]
	(n = 297)	Canadian general population/GM of blood Mn in female vs. male: 0.750 vs. 0.675 μg/dL* [2]
	(n = 7720)	USA general population (NHANES 2010-11)/GM of blood Mn in female vs. male: 0.99 vs. 0.87 μg/dL* [27]
Menopause	(n = 1826)	Korean general population KNHANES 2008–2009/GM of blood Mn in pre- vs. post-menopause: 1.443 vs. 1.296 μg/dL* [23]
Pregnancy	(n = 34)	Australian general population/Maternal blood Mn during pregnancy from 10 to 20 wk vs. 25 vs. 34 wk; 0.82 vs. 0.94 vs. 1.26 μg/dL [34]
	(n = 290)	Canadian general population/Maternal blood GM Mn during pregnancy at 3rd, vs. 2nd, vs. 1 st trimester vs. non-pregnant 1.56 vs. 0.95 vs. 0.85 and 0.746 μg/dL [35]
	(n = 66)	Swedish general population/Maternal blood median Mn during pregnancy at 3rd, vs. 2nd, vs. 1 st trimester 1.26 vs. 1.04 vs. 0.85 μg/dL [36]
	(n = 470)	Canadian general population/Maternal blood AM Mn during pregnancy at delivery vs. non-pregnant; 2.4 vs. (0.8–1.2) μg/dL [37]
	(n = 1085)	USA general population/blood GM Mn in pregnancy vs. non-pregnant; 1.19 vs. 1.02 μg/dL [27]
	(n = 265)	Korean general population/blood GM Mn in pregnancy; 2.25 μg/dL [8]
Age	(n = 2005)	Korean general population 20 y or more; KNHANES 2008/No significant change between 20′s and 40′s [19]
	(n = 7720)	US general population/blood GM Mn in age groups (1–5 years-old: 1.07 μg/dL; 6–11 years-old: 1.03 μg/dL; 12–19 years-old: 1.01 μg/dL; 20+ years-old: 0.91 μg/dL) [4]
	(n = 205)	German population/serum mean Mn in age groups (1, 4–6, 10–14, 22–75): 0.21, 0.14, 0.12, 0.08 μg/dL) [32]

GM, geometric mean; KNHANES, Korea National Health and Nutrition Examination Survey; NHANES, National Health and Nutrition Examination Survey. * Statistically significant.