New Birth Defect Risk: Dad's Vitamin Deficiency Father's lack of B9 jacks risk 28% in baby mice By Matt Cantor, Newser User Posted Dec 15, 2013 8:19 AM CST 4 comments Comments A father's diet may affect a baby's genetic makeup, a study suggests. (Shutterstock) (Newser) – Seems it's not just moms-to-be who need to watch what they eat. Men who don't get enough vitamin B9 may put their children at higher risk of birth defects, a study suggests. "It’s always put on the mother that it’s her health that determines the health of the baby," says lead author Sarah Kimmins. "But our research and that of some other groups is really showing that this is an outdated way of thinking." Researchers found that the diet of a male mouse could take a toll on genetic signaling in its sperm, the Los Angeles Times reports. If father mice had a vitamin B9, or folate, deficiency, baby litters had a 28% higher risk of birth defects, CBC reports. Those defects included skeletal, muscular, and facial abnormalities as well as webbed feet. Folate is already known to be important in a mother's diet, but plenty of people don't get enough of it, Kimmins notes. "We need to move forward as soon as possible with this work to validate in humans," she says. "It's too important not to."