Association of homocysteine with global DNA methylation in vegetarian Indian pregnant women and neonatal birth anthropometrics

Objective: The present study was designed to evaluate if plasma maternal folate, vitamin B-12 and homocysteine levels had an effect on maternal global DNA methylation and neonatal anthropometrics in Indian pregnant women. Methods: A total of 49 participants having completed >= 36 weeks of pregnancy were enrolled in the study. Estimation of folate was by Ion capture assay, vitamin B-12 by microparticle enzyme immunoassay, total homocysteine by fluorescence polarization immunoassay and global DNA methylation using Cayman's DNA methylation enzyme immunoassay (EIA) kit. Results: Folate and vitamin B-12 were inversely correlated to homocysteine in pregnant women consuming vegetarian and non-vegetarian diet. No difference in global DNA methylation was found between the vegetarian and non-vegetarian pregnant women. Folate and vitamin B-12 did not show association with global DNA methylation, however plasma total homocysteine of the vegetarian group showed significant correlation to global DNA methylation (r(2) = 0.49, p = 0.011). Plasma total homocysteine was inversely related to tricep skinfold (r(2) = -0.484, p = 0.01) and chest circumference (r(2) = -0.104, p = 0.04) of neonates in vegetarian group. Conclusion: Moderate vitamin B-12 deficiency in vegetarian pregnant women might be the cause of hyperhomocystinemia, hypermethylation when compared to vitamin B-12 sufficient non-vegetarian group.