Why boys are three times more likely to develop autism spectrum disorder than girls has remained a mystery for many years. One theory was that prenatal exposure to elevated testosterone levels was to blame. Earlier work has also shown that vitamin D deficiency in mothers at 20 weeks gestation is associated with an increased risk of autism spectrum disorders in children. Researchers from the University of Queensland decided to find out the mechanism of the effect of vitamin D deficiency on the occurrence of autistic disorder. To do this, the researchers conducted an experiment in animal models. It turned out that the connection between these conditions appears only for male children. After further analysis, the researchers found that vitamin D deficiency caused an increase in testosterone concentrations in the fetal brain and increased the child's risk of autism. The authors found that in embryos of mice with deficiencies in vitamin D, an enzyme that breaks down testosterone is blocked, which leads to the accumulation of an excess of this hormone. Researchers are not yet rushing to conclusions - it is not completely clear how increased testosterone concentration is associated with the development of autism spectrum disorders. Vitamin D deficiency is just one of many factors that can influence the onset of autism in newborns, scientists say. In future work, the researchers plan to take these factors into account and determine the exact mechanism of the influence of testosterone on the onset of mental disorder in boys.
