People with autism spectrum disorder (ASD) often have significant nutritional deficiencies, metabolic imbalances, and digestive problems. Many studies have previously looked at individual nutrients for ASD. This study was designed to look at the accumulative effect of using a wide range of dietary and nutritional interventions, including vitamin and mineral supplements, essential fatty acids, Epsom salt baths, carnitine, digestive enzymes, and a gluten-free, casein-free, soy-free (HGCSF) diet. The objective being to see if combining multiple interventions for a 12-month period, had greater benefits versus single nutrient interventions, and shorter trials. This US study recruited a wide age range of participants from 3-58yrs because it targeted, and was funded, by family groups of the Autism Society of Greater Phoenix. The study was deliberately single-blinded (meaning the participants knew what they were being given, but the clinical evaluators did not), as it was thought this would be more compelling and lead to less dropouts, especially considering the 12-month timing. In total 67 participants with ASD were recruited and 50 controls. Blood and urine samples were taking at the beginning and end of the study alongside autism severity assessments. Results showed an improvement in nutrient profiles for vitamins, minerals, fatty acids and carnitine alongside a significant decrease in homocysteine. There was an improvement in non-verbal IG test and cognitive function, and gastro-intestinal symptoms. There were no significant differences in complete blood count, blood chemistry panels or markers for inflammatory C-reactive protein (CRP). There was no change to BMI. Three exceptional cases of improvement were recorded in the control group and made into case studies highlighting improved physical strength and ability to walk, and resolution of urinary issues and pica eating disorder. Because it was single blinded there may be some ‘placebo effect’ but overall the researchers conclude that the study demonstrates how interventions can be safely and effectively implemented in families, with minimal adverse effect. And that combined nutrient and diet interventions should be considered for use in clinical practice.