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Vitamin D supplementation improves autism in children, according to new study

Posted on: December 7, 2016   by  Amber Tovey


In 2008, Dr. John Cannell, MD, Founder of Vitamin D Council published the first paper suggesting a relationship between low vitamin D status and increased risk of autism.  He created his hypothesis based on the data that illustrated an increased prevalence of autism in the regions of greater cloud cover and rainfall. Only observational studies had confirmed his hypothesis until now.

In a groundbreaking study, researchers proved that vitamin D supplementation reduces the symptoms of autism among children.

More than 3.5 million Americans live with autism spectrum disorder (ASD), affecting approximately 1 in 68 people. The prevalence of autism among U.S. children increased by nearly 120% from 2000 to 2010, coinciding with the increased prevalence of vitamin D deficiency in the U.S.

ASD describes a range of conditions categorized as neurodevelopmental disorders. Characteristics of autism include deficits in social skills, impairment in verbal and nonverbal communication and repetitive patterns of behavior, interests or activities.

Currently, there are no effective treatments for the core symptoms of autism. Thus, researchers all over the world are seeking solutions.

Vitamin D plays an essential role in neurodevelopment and gene regulation. More than 2,700 genes contain vitamin D receptors, and vitamin D regulates the expression of over 200 genes. Furthermore, vitamin D deficiency during pregnancy is associated with adverse effects for the baby, including an increased risk of autism. This evidence led researchers to recently conduct a randomized controlled trial (RCT), the gold standard of research, to evaluate the effects of vitamin D supplementation on autism in children.

The RCT consisted of 109 children with ASD, ages three to ten years. Half of the children were randomized to receive a daily vitamin D dose of 300 IU per kg of body weight, equivalent to 136 IU per pound, but no greater than 5,000 IU daily. The other half received a daily placebo pill. The experiment lasted for a total of four months.

The researchers assessed vitamin D levels, autism severity and social maturity of the children at the beginning and end of the study.

After four months, vitamin D supplementation significantly improved the core manifestations of ASD, which include irritability, hyperactivity, social withdrawal, stereotypic behavior and inappropriate speech. Whereas, the placebo group did not experience any significant improvements.

Furthermore, children who received vitamin D supplementation experienced  increased cognitive awareness, social awareness and social cognition compared to those who only received the placebo. Vitamin D supplementation significantly decreased repetitive hand movements, random noises, jumping and restricted interests.

The researchers concluded,

“This study is the first double-blinded RCT proving the efficacy of vitamin D3 in ASD patients…Oral vitamin D supplementation may safely improve signs and symptoms of ASD and could be recommended for children with ASD.”

The study also mentioned that the supplementation regimen was well tolerated among the children. Only five children experienced minor side effects during the four-month study period, such as skin rashes, itching and diarrhea.

Due to the lack of autism treatments currently available, the implications of this study could be life changing for many. However, the researchers reminded the readers that the study consisted of a relatively small number of patients, and further studies are needed to confirm the efficacy of vitamin D in ASD.


Tovey, A. & Cannell, JJ. Vitamin D supplementation improves autism in children, according to new study. The Vitamin D Council Blog & Newsletter, 2016.


Saad, K. et al. Randomized controlled trial of vitamin D supplementation in children with autism spectrum disorder. Journal of Child Psychology and Psychiatry, 2016.

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