A Randomised-Controlled Trial of Vitamin D and Omega-3 Long Chain Polyunsaturated Fatty Acids in the Treatment of Core Symptoms of Autism Spectrum Disorder in Children.

Mazahery et al. (2019) gave 3- to 8-year-old children with autism either vitamin D, omega-3 fish oil, both, or placebo every day for a year.

The team then checked if the kids’ social or sensory behaviors improved more than the placebo group.

Only a few small gains showed up, mainly in social awareness and sensory seeking.

Most comparisons were not significant, so the supplements did not create big, reliable change.

Two 2019 studies, C et al. and J et al., looked backward at newborn vitamin D blood spots. They found no link between low levels at birth and later autism diagnosis.

That seems to clash with Hajar’s weakly positive results, but the difference is timing: the babies were healthy and well-nourished, while Hajar gave extra nutrients to kids already diagnosed.

Portillo-Reyes et al. (2014) also ran an omega-3 RCT, yet in malnourished 8- to 12-year-olds. Over 70 % of those children showed clear neuropsych gains, far more than Hajar’s modest social bumps. The stronger effect may be because the Mexican kids lacked key nutrients to start with.

Chung et al. (2025) tested robot social coaching in an RCT and saw medium social gains, again beating the tiny shifts seen with pills. Together the pattern is: food supplements help most when diet is poor, while direct social teaching or brain stimulation tends to out-perform vitamins in well-fed autistic children.

If a family asks about fish oil or vitamin D, you can say small safety-tested doses are fine, but don’t promise big behavior change. Save your clinical hours for evidence-based social or parent programs, and reserve supplements for kids with confirmed dietary gaps.