Table 5.

Associations between maternal vitamin B₁₂ status and infant methylmalonic acid

Maternal variables	Trimester (T)	Model 1a			Model 2b
		n	Beta (s.e.m.)	P-value	Beta (s.e.m.)	P-value
Plasma vitamin B12,c pmol/l	T1	76	−0.43 (0.23)	0.060	−0.41 (0.26)	0.113
	T2	63	−0.55 (0.20)	0.006	−0.52 (0.20)	0.009
	T3	58	−0.55 (0.20)	0.006	−0.49 (0.20)	0.016
Vitamin B12 < 150 pmol/l	T1	76	0.47 (0.23)	0.036	0.49 (0.25)	0.046
	T2	63	0.65 (0.23)	0.005	0.66 (0.23)	0.004
	T3	58	0.80 (0.26)	0.002	0.76 (0.26)	0.004
Plasma MMA,c μmol/	T1	76	0.46 (0.16)	0.003	0.47 (0.16)	0.003
	T2	63	0.60 (0.18)	0.001	0.64 (0.17)	< 0.001
	T3	58	0.36 (0.16)	0.022	0.32 (0.16)	0.049
MMA >0.26 μmol/l	T1	76	0.66 (0.23)	0.005	0.63 (0.24)	0.008
	T2	63	0.56 (0.24)	0.020	0.66 (0.24)	0.006
	T3	58	0.46 (0.25)	0.062	0.42 (0.25)	0.084
Impaired vitamin B12 Statusd	T1	76	0.54 (0.23)	0.018	0.51 (0.23)	0.029
	T2	63	0.63 (0.23)	0.006	0.68 (0.22)	0.002
	T3	58	0.72 (0.25)	0.004	0.68 (0.25)	0.007
Plasma tHcy,c μmol/l	T1	76	0.26 (0.15)	0.090	0.24 (0.16)	0.140
	T2	63	0.34 (0.18)	0.063	0.34 (0.20)	0.083
	T3	58	−0.03 (0.19)	0.869	−0.01 (0.19)	0.951
cB12e	T1	76	−0.36 (0.12)	0.003	−0.35 (0.12)	0.005
	T2	63	−0.35 (0.12)	0.003	−0.37 (0.13)	0.004
	T3	58	−0.29 (0.13)	0.030	−0.33 (0.14)	0.016
Erythrocyte folate,c nmol/l	T1	76	−0.87 (0.30)	0.004	−0.94 (0.29)	0.001
	T2	63	−0.65 (0.34)	0.058	−0.74 (0.35)	0.036
	T3	58	−1.58 (0.42)	0.0002	−1.50 (0.42)	< 0.001

Abbreviations: BMI, body mass index; MMA, methylmalonic acid; SLI, standard of living index; tHcy, total homocysteine.

^aStatistical analyses: linear regression models were used to examine associations between maternal vitamin B₁₂ status and infant methylmalonic acid concentrations; models were adjusted for vitamin B₁₂ supplementation and gestational age of sample collection.

^bStatistical analyses: linear regression models were used to examine associations between maternal vitamin B₁₂ status and infant methylmalonic acid concentrations; models were adjusted for vitamin B₁₂ supplementation, gestational age of sample collection, maternal education (⩾ 10th grade vs <10), SLI (⩾ 28 vs <28), baseline total lymphocyte count, baseline BMI.

^cNatural logarithmically transformed to achieve normality.

^dImpaired vitamin B₁₂ status: plasma vitamin B₁₂<150 pmol/l plus MMA>0.26 μmol/l.

^ecB₁₂, a combined indicator of vitamin B₁₂ status modified for three biomarkers (vitamin B₁₂, MMA and tHcy), was calculated using the method developed by Fedosov et al.²⁰