Hair Metals Test Analysis has been used to assess sufficiency of Iodine, Selenium and Molybdenum in children with autism. Iodine deficiency was found to be very common, as well as Selenium deficiency and Molybdenum deficiency. All children tested had a deficiency in at least one of the metals. Each of Iodine, Selenium and Molybdenum is an essential cofactor in the activation of vitamin B2, and hence potentially each child was also deficient in functional vitamin B2. Functional vitamin B2 is an essential co-factor in the activity of vitamin B12, and potentially this would also mean that each child was deficient in functional vitamin B12 – a known predisposing factor for developmental delay.