B VS. DDT

Too much DDT, too few B vitamins: Neither one is good for reproductive health. But combine them, says Xiaobin Wang, MD, ScD, MPH, and you’ve got a double whammy. The Zanvyl Krieger Professor in Child Health and director of the Center on the Early Life Origins of Disease had previously shown that deficiencies in B vitamins and high levels of DDT could each individually interfere with a woman’s ability to become pregnant. This matters: In many parts of the developing world, grains are not fortified with B vitamins, and DDT is still used to fight malaria. 

Now, in a study in the American Journal of Clinical Nutrition, Wang and her colleagues demonstrate that these factors can also work in concert, raising the risks of very early miscarriage and extending the amount of time it takes to get pregnant. Adequate levels of B vitamins, meanwhile, can ward off the negative effects of high DDT exposure.

“What we’ve done here,” Wang says, “is link the two pieces together.” In a study of 291 female textile workers in China, those who had relatively high levels of DDT and were also deficient in one of several different B vitamins took longer to become pregnant—almost twice as long if they were deficient in two or more—than those with low levels of DDT and no deficiencies. They were also more likely to suffer multiple early miscarriages. Women with sufficient B vitamins in their blood got pregnant faster and were less likely to miscarry.

The research indicates that women of reproductive age who hail from regions where DDT levels are high could benefit from having more B vitamins in their diet. More generally, says Wang, it also suggests that “when we think of nutrition and environmental toxins, we shouldn’t think of them in isolation.”