It is a commonly held belief that children with autism can experience a substantial nutritional boost from following such specialized diets as gluten-free and casein-free (GFCF) diets. In addition, many parents also rely on dietary supplements to help their children follow their special diets and provide them with nutrients they may be lacking.

However, a new study just released in the Journal of the Academy of Nutrition and Dietetics has found that these GFCF and supplement regimens can in fact still leave children with autism deficient in certain nutrients, such as calcium. On the other hand, special diets and supplements can further exacerbate this issue by causing children to take excessive amounts of certain nutrients, such as Vitamin A.

“Many families try a GFCF diet in an attempt to improve symptoms of ASD,” Dr. Patricia A. Stewart, assistant professor of Pediatrics at the University of Rochester Medical Center, said in a statement. “While 19 percent of all Autism Speaks Autism Treatment Network (AS ATN) participants were reported to be on a GFCF diet, 12 percent of the children in the subgroup participating in this study were given a GFCF diet and were significantly more likely to use nutritional supplements (78 percent vs. 53 percent). However, the micronutrient intake of children on or off the diet was remarkably similar.”

To gain a better understanding of the effects of GFCF diets and supplements, Stewart and her colleagues recruited 368 children between the ages of 2 and 11 who had been diagnosed with autism, Asperger’s disorder, or a pervasive developmental disorder. Researchers then required caregivers to keep three-day food journals that kept track of all foods, beverages, and nutritional supplements that a child consumed in that period.

Upon analyzing the children’s food diaries, the researchers discovered that the children with autism spectrum disorder were consuming amounts of nutrients that were tantamount to what other children who did not have autism were consuming. They also had the same deficiencies as seen in the general population.

Furthermore, even in children who took supplements, upwards of 55 percent of these children with ASD remained deficient in calcium, while nearly 40 percent did not receive enough vitamin D.

Meanwhile, the children on a GFCF diet tended to eat far more magnesium and vitamin E, but they were still generally deficient in calcium.

The researchers thus found that many of these special diets and supplements are ultimately unnecessary because even children with picky eating habits still get most of their essential nutrients from the food they eat due to the fact that many of today’s foods are fortified with essential vitamins and minerals. The study suggested that this could explain why some kids with autism are getting too much of certain nutrients, such as vitamin A, folic acid, and zinc.

“Few children with ASD need most of the micronutrients they are commonly given as multivitamins, which often leads to excess intake that may place children at risk for adverse effects,” Stewart said. “When supplements are used, careful attention should be given to adequacy of vitamin D and calcium intake,” she added.

While this study will still need to be further examined and tested by other researchers, it is clear that a fundamental change in the way we perceive how to best feed children with autism might be on the horizon.