The study published in the Journal of the Academy of Nutrition and Dietetics monitored 288 children with autistic spectrum disorder (ASD) – including autistic disorder, Asperger’s disorder and pervasive developmental disorder – across various sites between the years 2009 to 2011.
Over half, 56% of the children used dietary supplements, especially multivitamin/mineral formulations.
Supplements did not, however, correct the most common micronutrient deficits seen in the children with ASD, found the study – those of vitamin D, calcium, potassium, pantothenic acid and choline.
Almost a third of the children remained deficient for vitamin D, and up to half of them for calcium, say the authors.
The reverse problem was also observed because the study found excessive intakes as a result of the use of supplements. Across all ages of children, supplementation led to excess intakes of:
Vitamin A, folate and zinc
Vitamin C and copper among children aged 2-3 years
Manganese and copper for children aged 4-8 years.
The monitoring involved detailed records of diet and supplements over 3 days, and the use of a gluten/casein-free (GFCF) diet was found to be associated with a higher level of supplementation – yet these children received similar levels of micronutrient intake overall as the other children.
“Many families try a GFCF diet in an attempt to improve symptoms of ASD,” explains dietitian and lead investigator Patricia Stewart, PhD, assistant professor of pediatrics at the University of Rochester Medical Center, NY.
“While 19% of all […] participants were reported to be on a GFCF diet, 12% 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% versus 53%); however, the micronutrient intake of children on or off the diet was remarkably similar.”
‘More than half of children with ASD supplemented – at an average of two a day’
The 2- to 11-year-olds studied were recruited from five US sites – Cincinnati Children’s Hospital, University of Arkansas, University of Colorado, University of Pittsburgh and the University of Rochester.
A registered dietitian nutritionist trained caregivers to do the 3-day detailed records, noting the amounts of all foods, beverages and nutritional supplements consumed, including brand names and the recipes used.
Accurate recording of details about nutritional supplements was ensured by taking photographs of the labels.
“Among the 56% of children with ASD in this study who took supplements,” say the authors, “an average of two supplements were used per day.”
Ironically, it was the children who were already consuming “more micronutrients in adequate amounts from food alone” who were more likely to supplement. Also, the authors found:
Dr. Stewart says professional help with diet would be best:
“In clinical practice, each patient needs to be individually assessed for potential nutritional deficiencies or excess.
“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. When supplements are used, careful attention should be given to adequacy of vitamin D and calcium intake.”