 From VOA Learning English, this is the help report in special English. Women who took folic acid in early pregnancy were less likely to have a child with autism than other women in a recent study. Folic acid is a B vitamin that helps the body build and repair cells. The study, however, did not prove that folic acid can prevent childhood autism. Children with autism have problems communicating and socializing with other people. Researchers at the Norwegian Institute of Public Health looked at records of more than 85,000 children born between 2002 and 2008. The study asked mothers to describe their diets and any vitamin supplements they took before and during their pregnancies. Research leader Paul Surin and his colleagues compared the women who took folic acid supplements to those who did not. He says the women who took folic acid in early pregnancy had a 40% reduction in the risk of having a child with autism. He says the best time to take folic acid is from four weeks before to eight weeks after the start of pregnancy. The researchers found that taking folic acid halfway through pregnancy had no effect. The cause of autism is not known. Several genes may be involved in the disorder. Folic acid has been linked to the development of a protective covering called the neural tube in a fetus. Women who did not get enough folic acid are at risk of giving birth to infants with part of their spinal cord or brain exposed. This disabling condition is called spina bifida. Dark leafy vegetables, asparagus, broccoli and citrus fruit are rich sources of folate. Folate is the naturally occurring form of folic acid. Folate is also found in peas, lentils, beans, eggs, yeast and liver. For VOA Learning English, I'm Laurel Bowman.