The association between first trimester micronutrient intake, MTHFR genotypes, and global DNA methylation in pregnant women

Figures & data

Table I.  Selected maternal characteristics of the population for which DNA methylation in maternal blood was evaluated (n = 195).

Maternal characteristics	n	%	DNA hypomethylation
			n	Prevalence	Crude RR (95% CI)
Age
<20 years old	64	32.8	35	54.7	1.00
20–24 years old	74	38.0	31	41.9	0.77 (0.54, 1.08)
≥24 years old	57	29.2	34	59.6	1.09 (0.80, 1.48)
Education
≤12 years	158	81.0	81	51.3	1.00
>12 years	37	19.0	19	51.4	1.00 (0.71, 1.42)
Parity
No previous pregnancy	165	84.6	87	52.7	1.00
≥1 previous pregnancy	30	15.4	13	43.3	0.82 (0.53, 1.27)
BMI
Underweight	15	7.7	8	53.3	1.04 (0.63, 1.72)
Normal weight	125	64.1	64	51.2	1.00
Overweight	42	21.5	23	54.8	1.06 (0.77, 1.48)
Obese	13	6.7	5	38.5	0.75 (0.37, 1.52)
Tobacco use during pregnancy
None	175	89.7	91	52.0	1.00
Used	20	10.3	9	45.0	0.86 (0.52, 1.43)
Alcohol use during pregnancy
None	164	84.1	86	52.4	1.00
≥1 cup/week	31	15.9	14	45.2	0.86 (0.57, 1.30)
MTHFR 1298
AA	158	81.0	78	49.4	1.00
AC + CC	37	19.0	22	59.5	1.20 (0.88, 1.64)
MTHFR 677
CC	31	15.9	16	51.6	1.00
CT + TT	164	84.1	84	51.2	0.99 (0.68, 1.44)

Table II.  Relative risks of DNA hypomethylation in maternal blood due to low levels of micronutrients in a Mexican pregnancy cohort (n = 195).

Micronutrients (mg/day)	Methylation		Risk Ratio (95% CI)
	Hyper n	Hypo n	Unadjusted	Adjusted*
B1 (Thiamine)
≥1.4	81	80	1.00	1.00
<1.4	14	20	1.18 (0.86, 1.63)	1.12 (0.75, 1.67)
B2 (Riboflavin)
≥1.4	81	83	1.00	1.00
<1.4	14	17	1.08 (0.76, 1.54)	0.97 (0.63, 1.49)
B6 (Pyridoxine)
≥1.9	46	30	1.00	1.00
<1.9	49	70	1.45 (1.06, 1.99)	1.80 (1.24, 2.61)
B9 (Folate)
≥0.6	9	8	1.00	1.00
<0.6	86	92	1.10 (0.65, 1.85)	0.98 (0.56, 1.73)
B12 (Cobalamin)
≥0.0026	62	68	1.00	1.00
<0.0026	33	32	0.94 (0.70, 1.27)	0.89 (0.65, 1.21)
Betaine
≥31.108	52	46	1.00	1.00
<31.108	43	54	1.19 (0.90, 1.56)	1.15 (0.843, 1.56)
Choline
≥425	23	20	1.00	1.00
<425	72	80	1.13 (0.79, 1.61)	1.01 (0.66, 1.53)
Methionine
≥1755.311	51	46	1.00	1.00
<1755.311	44	54	1.16 (0.88, 1.53)	1.08 (0.74, 1.59)

*Adjusted by maternal age and total caloric consumption.

Table III.  Relative risks of DNA hypomethylation in maternal blood due to low levels of vitamin B₆ in a Mexican pregnancy cohort stratified by MTHFR status (N = 195).

VitaminB6 (mg/d)	MTHFR 677*^,†				MTHFR 1298*^,‡
	CC		CT/TT		AA		AC/CC
	n	aRR	n	aRR	n	aRR	n	aRR
≥1.9	15	1.0	61	1.0	63	1.0	13	1.0
<1.9	16	1.51 (0.57, 4.03)	103	1.79 (1.13, 2.85)	95	1.62 (1.01, 2.58)	24	2.24 (0.88, 5.67)

*Adjusted by maternal age and total caloric consumption. ^†Breslow–Day test of homogeneity p-value = 0.02. ^‡Breslow–Day test of homogeneity p-value = 0.79.