Circulating levels of micronutrients and risk of infections: a Mendelian randomization study

Table 2 Source of exposure genome-wide association study summary data

Exposure	Main analysis^a		Seconary analysis^b			Population ancestry	Reference
Exposure	Number of SNPs	% of variance explained		Number of SNPs	% of variance explained	Population ancestry	Reference
Ca^c	2	0.15		3	0.18	European	[5]
Cu	2	4.36	QIMR	6	7.10^d	European	[6, 20]
Cu			Jäger et al.	7	6.55	European	[6, 20]
Fe	13	3.01		96	5.37	European	[7]
Mg^c	6	0.01		8	0.01	European	[8]
Se	1	2.40	QIMR	6	10.2	European	. [6]
Se			ALSPAC	7	8.06	European	. [6]
Zn	2	4.25		7	8.66	European	[6]
Beta-carotene	1	4.59		–	–	European	[9]
Folate^c	2	0.58		3	0.67	European	[10]
Vitamin B6^c	1	0.67		–	–	European	[12]
Vitamin B12	10	4.36		11	4.43	European	[10]
Vitamin C	11	1.90		20	2.28	European	[13]
Vitamin D	59	1.98		75	2.39	European	[14, 15]

Missing data is denoted by “–”
Abbreviations: Ca calcium, Cu copper, Fe iron, Mg magnesium, Se selenium, Zn zinc
^aFor the main analyses, only independent (r² < 0.001 within 10,000-kb windows) and strongly associated (P ≤ 5E−08) variants were used
^bFor the secondary analyses, only variants (r² < 0.01 within 10,000-kb windows) suggestively associated (P ≤ 5E−06) variants were used
^cCa, Mg, and folate were excluded due to the variance explained < 1%
^dWe observed extreme values for R², which was explained by one extremely outlying SNP; rs12582659 had an R² of 17.80%

ISSN: 1741-7015