Table 4.

Interactions between folate-associated genotypes by multivitamin supplement use

		No Multivitamin Supplement use†			Multivitamin Supplement use
Gene	SNP	Sibships	OR (95% CI)‡	P-value§	Sibships	OR (95% CI)‡	P-value	P-interaction
DHFR	rs1677693	565	0.69 (0.58–0.82)	0.000021	637	0.91 (0.78–1.07)	0.299	0.000899
DHFR	rs1643659	564	0.69 (0.58–0.82)	0.000026	637	0.91 (0.78–1.07)	0.223	0.000986
MTR	rs4659744	565	0.76 (0.67–0.88)	0.000108	637	0.97 (0.85–1.11)	0.624	0.000265
MTRR	rs16537	565	0.79 (0.68–0.91)	0.0017	637	1.04 (0.91–1.20)	0.547	0.000057
MAT2A	rs1446669	564	0.81 (0.69–0.95)	0.0084	634	1.13 (0.98–1.32)	0.103	0.000033
MAT2A	rs6739015	562	0.83 (0.72–0.96)	0.0137	633	1.09 (0.95–1.25)	0.238	0.000030
MAT2A	rs10179195	565	0.84 (0.73–0.97)	0.0142	637	1.07 (0.94–1.22)	0.338	0.000063
MAT2A	rs699664	564	0.80 (0.68–0.93)	0.0041	635	1.06 (0.92–1.23)	0.428	0.000107

^†Multivitamin supplement users were defined as those reporting ever use of supplements regularly (at least 2x/week for more than a month).

^‡OR’s and 95% confidence limits computed using conditional logistic regression with sibship as the matching factor and controlling for age and sex.

^§The Bonferroni-adjusted p-value based on an analysis of 395 tagSNPs is 0.00013.