In this study, researchers examined hair zinc concentrations in 1,967 children with autistic disorders (1,553 males and 414 females). The incidence rate of zinc deficiency in infant group aged 0-3 years-old was estimated 43.5 % in male and 52.5 % in female. The authors comment "these findings suggest the possibility that some of autistic children and suspects may be improved by nutritional approach supplementing deficient nutrients such as zinc".
Yasuda H, Yoshida K, Yasuda Y, Tsutsui T. Infantile zinc deficiency: Association with autism spectrum disorders. Sci Rep. 2011;1:129.