A combination of low vitamin B12 levels and certain genetics (for the methionine synthase reductase (MTRR) and transcobalamin II (TC) genes) increased the risk of congenital heart defects by about 35 and 100 per cent, respectively, report the researchers in the journal Molecular Genetics and Metabolism.
"Therefore, it might be favorable to advise women to use a diet rich in vitamin B12 and eventually a vitamin B12 supplement in addition to a folic acid supplement in the periconception period to achieve an optimal vitamin B12 status," wrote Anna Verkleij-Hagoort from Erasmus MC, University Medical Center in Rotterdam.
The importance of B vitamins, particularly folate, to prevent birth defects is well established.
Source: Molecular Genetics and Metabolism (Elsevier)
Published online ahead of print 15 January 2008, doi:10.1016/j.ymgme.2007.12.002
"Genetic and lifestyle factors related to the periconception vitamin B12 status and congenital heart defects: A Dutch case-control study"
Authors: A.C. Verkleij-Hagoort, L.M.J.W. van Driel, J. Lindemans, A. Isaacs, E.A.P. Steegers, W.A. Helbing, A.G. Uitterlinden and R.P.M. Steegers-Theunissen