B vitamins may promote female fertility

According to a new US study, an adequate supply of B vitamins in women seems to increase their chances of becoming and staying pregnant even when they have high blood concentrations of a common pesticide.

The observational study measured the blood concentrations of vitamin B6, vitamin B12, folate, and the pesticide DDT of 291 Chinese women before conception and documented cases of pregnancy and early miscarriage over 2 years (1). The study results showed that, compared to women with adequate B vitamin and low DDT levels, incidence rates of pregnancy were reduced in women with B vitamin deficiency and high DDT concentrations. In women with a sufficient vitamin B12 supply, DDT was not associated with the incidence of pregnancy. In contrast, in women with a vitamin B12 deficiency, high DDT was associated with a lower incidence of pregnancy. The chance of early miscarriage decreased significantly in women with higher folate levels and high DDT concentrations.

The researchers concluded that sufficient blood concentrations of vitamin B12 and folate may help protect against adverse reproductive effects of DDT exposure. DDT is still used to kill mosquitoes in many countries where malaria remains a serious public health concern. The United States banned the pesticide in 1972. China, where the study was conducted, followed suit in 1984. However, DDT can remain in the body and environment for decades. Previous research has shown that high levels of DDT in the body can increase the risk of early miscarriage. Better nutrition in countries where DDT is still in wide use – including fortifying foods with B vitamins – could improve pregnancy outcomes, the scientists noted.

1. Ouyang F. et al. Preconception serum 1,1,1-trichloro-2,2,bis(p-chlorophenyl)ethane and B-vitamin status: independent and joint effects on women's reproductive outcomes. American Journal of Clinical Nutrition. 2014; 100(6):1470-1478.