TY - JOUR
T1 - Vitamin B-12 Status during Pregnancy and Child's IQ at Age 8: A Mendelian Randomization Study in the Avon Longitudinal Study of Parents and Children
AU - Bonilla, C.
AU - Lawlor, D.A.
AU - Taylor, A.E.
AU - Gunnell, D.J.
AU - Ben-Shlomo, Y.
AU - Ness, A.R.
AU - Timpson, N.J.
AU - Pourcain, B.S.
AU - Ring, S.M.
AU - Emmett, P.M.
AU - Smith, A.D.
AU - Refsum, H.
AU - Pennell, Craig
AU - Brion, Marie-Jo
AU - Smith, G.D.
AU - Lewis, S.J.
PY - 2012/12/5
Y1 - 2012/12/5
N2 - Vitamin B-12 is essential for the development and maintenance of a healthy nervous system. Brain development occursprimarily in utero and early infancy, but the role of maternal vitamin B-12 status during pregnancy on offspring cognitivefunction is unclear. In this study we assessed the effect of vitamin B-12 status in well-nourished pregnant women on thecognitive ability of their offspring in a UK birth cohort (ALSPAC). We then examined the association of SNPs in maternalgenes FUT2 (rs492602) and TCN2 (rs1801198, rs9606756) that are related to plasma vitamin B-12, with offspring IQ.Observationally, there was a positive association between maternal vitamin B-12 intake and child’s IQ that was markedlyattenuated after adjustment for potential confounders (mean difference in offspring IQ score per doubling of maternal B-12intake, before adjustment: 2.0 (95% CI 1.3, 2.8); after adjustment: 0.7 (95% CI 20.04, 1.4)). Maternal FUT2 was weaklyassociated with offspring IQ: mean difference in IQ per allele was 0.9 (95% CI 0.1, 1.6). The expected effect of maternalvitamin B-12 on offspring IQ, given the relationships between SNPs and vitamin B-12, and SNPs and IQ was consistent withthe observational result. Our findings suggest that maternal vitamin B-12 may not have an important effect on offspringcognitive ability. However, further examination of this issue is warranted.
AB - Vitamin B-12 is essential for the development and maintenance of a healthy nervous system. Brain development occursprimarily in utero and early infancy, but the role of maternal vitamin B-12 status during pregnancy on offspring cognitivefunction is unclear. In this study we assessed the effect of vitamin B-12 status in well-nourished pregnant women on thecognitive ability of their offspring in a UK birth cohort (ALSPAC). We then examined the association of SNPs in maternalgenes FUT2 (rs492602) and TCN2 (rs1801198, rs9606756) that are related to plasma vitamin B-12, with offspring IQ.Observationally, there was a positive association between maternal vitamin B-12 intake and child’s IQ that was markedlyattenuated after adjustment for potential confounders (mean difference in offspring IQ score per doubling of maternal B-12intake, before adjustment: 2.0 (95% CI 1.3, 2.8); after adjustment: 0.7 (95% CI 20.04, 1.4)). Maternal FUT2 was weaklyassociated with offspring IQ: mean difference in IQ per allele was 0.9 (95% CI 0.1, 1.6). The expected effect of maternalvitamin B-12 on offspring IQ, given the relationships between SNPs and vitamin B-12, and SNPs and IQ was consistent withthe observational result. Our findings suggest that maternal vitamin B-12 may not have an important effect on offspringcognitive ability. However, further examination of this issue is warranted.
U2 - 10.1371/journal.pone.0051084
DO - 10.1371/journal.pone.0051084
M3 - Article
C2 - 23227234
SN - 1932-6203
VL - 7
SP - 9pp
JO - PLoS One
JF - PLoS One
IS - 12
ER -