Addressing Common Nutritional Deficiencies in Autism

Consumption of total fruit and white vegetables, as well as other dietary factors, may contribute to
Consumption of total fruit and white vegetables, as well as other dietary factors, may contribute to
Ann Neumayer, MD, suggests that giving too many supplements can be harmful as well as giving too few.

Children with autism spectrum disorders (ASD) present with multiple eating and nutrition challenges, and the core features of ASD can make it especially difficult to recognize and address such problems. Findings published in 2013 show that children with autism experience eating and feeding problems at 5 times the rate of non-ASD peers.1 “Food selectivity–or only eating a narrow variety of foods–is the most prominent feeding concerns among children with autism,” says William Sharp, PhD, director of the Pediatric Feeding Disorders Program at Marcus Autism Center and assistant professor of pediatrics at Emory University School of Medicine in Atlanta. It typically involves strong preferences for starchy and processed foods and snack foods, along with a bias against fruits and vegetables.2 Food selectivity is distinct from the picky eating commonly seen in young children, and evidence indicates that it is a “chronic condition that persists into adolescence and adulthood and may increase the risk of diet-related diseases over time,” he told Psychiatry Advisor.

Additionally, strong refusal behaviors are more likely to occur in children with ASD. They may respond to routine feeding demands or the sight or smell of non-preferred foods with disruptive behaviors such as crying, throwing objects, or other aggressive actions. “As a result, children with autism may refuse to sit at the family dinner table and families may avoid social events that involve food, such eating at restaurants, attending birthday parties or religious observances that include food,” he says.

These eating issues can result in serious health risks, including nutritional deficiencies and medical complications. Children with ASD have been found to have lower vitamin D and calcium intake from food compared with that of their typically developing peers, and children with and without autism generally do not consume sufficient amounts of those nutrients or vitamin E, potassium, and choline, according to Ann Neumayer, MD, a neurologist and medical director of the Lurie Center for Autism at Massachusetts General Hospital for Children. A cross-sectional study published in 2015 in the Journal of the Academy of Nutrition and Dietetics investigated micronutrient intake and the use of supplements in 288 children aged 2–11 with ASD.3 The results show that while 56% of the sample was taking nutritional supplements, there remained deficits in vitamin D, calcium, potassium, pantothenic acid, and choline. Nearly one third of participants were deficient in vitamin D, for example, and up to 54% were calcium-deficient.

“Vitamin deficiencies can have many implications for the health and functioning of any growing child or adult,” Dr Neumayer told Psychiatry Advisor. “Calcium and vitamin D deficiencies can affect bone development, B vitamin deficiency can affect the brain and nervous system, and vitamin C deficiency can affect wound healing, bleeding, and bruising, as well as conditions affecting the skin.” Children with ASD are also at greater risk of obesity, because their narrow food preferences most often result in deficits in variety, not volume. Their most common dietary pattern includes high intake of calorie-dense but nutritionally-void foods, so they usually eat sufficient amounts to fulfill gross energy needs but not micronutrient needs, explains Dr Sharp. “Poor dietary diversity also coincides with the success and common use of second generation antipsychotic medications to manage disruptive behaviors in children with ASD–these medications are associated with weight gain and adverse metabolic effects,” he says. In addition, extreme cases of food selectivity have been linked with severe malnutrition and relatively uncommon diseases such as scurvy, rickets, vision loss, and iron deficiency.

Routine diagnostic screening of children with ASD should include assessment of dietary intake and mealtime concerns to assess overall dietary risk. “An easy method for screening involves asking parents if their child regularly consumes foods from all food groups,” suggests Dr Sharp. If the child rejects all items from one or more food groups, it may be necessary to involve a dietitian to assess potential nutritional deficiencies. If any are detected, referral to a multidisciplinary feeding clinic may be warranted because established guidelines for encouraging dietary diversity “may be neither practical nor feasible given the combination of behavioral, developmental, medical, and social deficits associated with autism,” he says. Clinicians should also consider the possibility that food selectivity is being driven by underlying medical concerns that make eating certain foods painful or uncomfortable, which many children with ASD would be unable to convey because of communication deficits.

Another important point for practitioners to keep in mind is that even though many children with ASD are given dietary supplements, they may not be getting sufficient amounts of the right ones, says Dr Neumayer, and “giving too many supplements can be harmful as well as giving too few.” In the 2015 study, the intake of dietary supplements was associated with excess levels of vitamin A, folate, zinc, copper, and manganese. Practitioners should monitor nutrient levels and prescribe supplements as indicated. In a new study co-authored by Neumayer regarding prescribing practices of providers treating children with ASD, a low percentage of the sample was taking vitamin D and calcium supplements, and very few children had been tested for 25(OH)D levels.4

“Any discussion regarding food selectivity in autism would be remiss without addressing the proliferation of caregiver-mediated dietary restrictions in this population,” including the gluten-free, casein-free diet (GFCF) and the ketogenic diet, notes Dr Sharp. Empirical evidence does not support the use of these approaches as ASD-focused treatments, he says, and restricting or eliminating food groups may further increase the risk of nutritional deficiencies associated with food selectivity.5 “Clinicians should be prepared to counsel caregivers on the lack of evidence on the effectiveness of dietary intervention to influence core symptoms of ASD, while concurrently emphasizing the importance of promoting a healthy and well-balanced diet in this population.”

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1. Sharp WG, Berry RC, McCracken C, et al. Feeding problems and nutrient intake in children with autism spectrum disorders: a meta-analysis and comprehensive review of the literature. J Autism Dev Disord. 2013; 43(9):2159-73. 

2. Berry RC, Novak P, Withrow N, et al. Nutrition Management of Gastrointestinal Symptoms in Children with Autism Spectrum Disorder: Guideline from an Expert Panel. J Acad Nutr Diet. 2015; 115(12):1919-27.

3. Stewart PA, Hyman SL, Schmidt BL, et al. Dietary Supplementation in Children with Autism Spectrum Disorders: Common, Insufficient, and Excessive. J Acad Nutr Diet. 2015; 115(8):1237-48. 

4. Srinivasan S, O’Rourke J, Bersche Golas S, Neumeyer A, Misra M. Calcium and Vitamin D Supplement Prescribing Practices among Providers Caring for Children with Autism Spectrum Disorders: Are We Addressing Bone Health? Autism Res Treat.  2016; 2016:6763205.

5. Hyman SL, Stewart PA, Foley J, et al. The Gluten-Free/Casein-Free Diet: A Double-Blind Challenge Trial in Children with Autism. J Autism Dev Disord. 2016; 46(1):205-20.