Open-Label Trial of Vitamin D3 Supplementation in Children with Autism Spectrum Disorder

Abstract

JOURNAL OF CHILD AND ADOLESCENT PSYCHOPHARMACOLOGY Volume X, Number x, 2016 a Mary Ann Liebert, Inc. Pp. 1–10 DOI: 10.1089/cap.2015.0159 Original Article Randomized, Placebo-Controlled Trial of Methyl B12 for Children with Autism Robert L. Hendren, DO, 1 S. Jill James, PhD, 2 Felicia Widjaja, MPH, 1 Brittany Lawton, BS, 1 Abram Rosenblatt, PhD, 1 and Stephen Bent, MD 1 Abstract Objective: Children with autism spectrum disorder (ASD) have been reported to have reduced ability to methylate DNA and elevated markers of oxidative stress. We sought to determine if methyl B12, a key metabolic cofactor for cellular methylation reactions and antioxidant defense, could improve symptoms of ASD. Methods: A total of 57 children with ASD were randomly assigned to 8 weeks of treatment with methyl B12 (75 lg/kg) or saline placebo every 3 days in a subcutaneous injection. The primary outcome measure was overall improvement in symptoms of ASD as measured by the Clinical Global Impressions-Improvement (CGI-I) score. Secondary outcome mea- sures included changes in the Aberrant Behavior Checklist (ABC) and the Social Responsiveness Scale (SRS). Laboratory measures of methionine methylation and antioxidant glutathione metabolism were assessed at baseline and 8 weeks. Results: A total of 50 children (mean age 5.3 years, 79% male) completed the study. The primary outcome measure – the clinician rated CGI-I score – was statistically significantly better (lower) in the methyl B12 group (2.4) than in the placebo group (3.1) (0.7 greater improvement in the methyl B12 group, 95% CI 1.2–0.2, p = 0.005). Clinical improvement among children treated with methyl B12 was positively correlated with increases in plasma methionine ( p = 0.05), decreases in S-adenosyl-l- homocysteine (SAH) ( p = 0.007) and improvements in the ratio of S-adenosylmethionine (SAM) to SAH ( p = 0.007), indi- cating an improvement in cellular methylation capacity. No improvements were observed in the parent-rated ABC or SRS. Conclusions: Methyl B12 treatment improved clinician-rated symptoms of ASD that were correlated with improvements in measures of methionine metabolism and cellular methylation capacity. Clinical Trial Registry: Efficacy Study of Subcutaneous Methyl B12 in Children with Autism: NCT01039792 (clinical trials.gov1). Introduction with autism had significantly lower plasma methionine, S- adenosylmethionine (SAM), homocysteine, cystathionine, cysteine, and total glutathione as well as significantly higher levels of S-adenosyl-l-homocysteine (SAH), adenosine, and oxidized gluta- thione. These laboratory changes were consistent with increased oxidative stress and impaired methylation capacity in children with ASD ( James et al. 2004). As shown in Figure 1, these abnormalities are related to three interconnected metabolic pathways known col- lectively as methionine transmethylation/transsulfuration metabo- lism (Hirsch et al. 2008; Kalinina et al. 2014; Watson et al. 2014). A second study in 2006 of 80 children with ASD and 73 controls again demonstrated the same pattern of methylation deficit and oxidative stress ( James et al. 2006). A more recent study in 2012 examined 68 children with ASD, 40 unaffected siblings, and 54 age- matched unaffected, unrelated control children. Reduced methyla- tion capacity was associated with DNA hypomethylation and reduced glutathione antioxidant defense in the children with ASD but not in their unaffected siblings or control children (Melnyk et al. A utism spectrum disorder (ASD) is a complex neurodeve- lopmental disorder characterized by deficits in social inter- action and restricted, repetitive patterns of behavior that now affects 1 in 68 children (Developmental Disabilities Monitoring Network Surveillance Year Principal and Centers for Disease Control and Prevention 2014). ASD has a significant genetic component, with up to 25% of cases being caused by an identifiable genetic defect (Huguet et al. 2013). However, two recent epide- miologic studies have concluded that environmental influences have a greater contribution than genetic factors in the etiology of autism (Hallmayer et al. 2011; Sandin et al. 2014). Many metabolic processes have shown specific deficits in children with ASD, including both cellular methylation and glutathione- mediated antioxidant defense (Rossignol and Frye 2012). In 2004, James et al. reported findings of a small study of 20 children with autism compared with 33 healthy controls, and found that children Department of Psychiatry, University of California, San Francisco, California. Arkansas Children’s Hospital Institute, Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas. Funding: This study was supported by a grant from Autism Speaks (grant #3031 to Dr. Hendren).