Researchers have been working to understand the link between vitamin D and autism for years. Autism now affects about one in every 68 children, according to statistics presented by Autism Speaks, which makes autism one of the fastest growing developmental disorders in the United States and there is no cure. Early studies suggest low vitamin D levels increase the risk of autism in children. Now new research, published in the Journal of Child Psychology and Psychiatry, shows that vitamin D supplementation may improve the symptoms of autism.
ASD is a complex neurodevelopmental syndrome, characterized by defects in social interaction, communication impairment, and specific patterns of activities and interests. Symptoms of autism in toddlers include significant language delays. When the child does communicate, his facial expressions, movements, tone of voice and gestures that may not match what the child is saying. Failed communication can lead to the child feeling frustration and exhibiting inappropriate behavior, such as screaming and grabbing. Other symptoms of ASD include repetitive behaviors, intense preoccupations, and obsessions.
Autism typically develops in children before the age of 3 years. A number of environmental and genetic factors can increase the risk of autism. Several older studies show that vitamin D deficiencies may play a role in the development of autism; the newest study suggests vitamin D supplementation may reduce the symptoms.
About Vitamin D
Vitamin D plays an important part in brain homeostasis, neurodevelopment, and aging. The vitamin also has a significant role in genetics and gene regulation, binding to more than 2,700 genes and regulating the expression of more than 200 genes.
Vitamin D is a fat-soluble vitamin found naturally in a few foods, including cod liver oil and swordfish, and added to orange juice and other foods. Some dietary supplements contain vitamin D. The human body can make vitamin D through exposure to sunlight. Low consumption of foods containing vitamin D and limited exposure to sunshine can decrease vitamin D levels.
There are two main forms of vitamin D: vitamin D2 and vitamin D3. Certain plants and fungi make vitamin D2; animals make vitamin D3. Exposure to sunlight helps the body make vitamin D3. . Vitamin manufacturing companies offer vitamin D in both D2 and D3. The difference is noteworthy in that the researchers in the newest study administered vitamin D3 rather than vitamin D2 to children with autism.
Previous Research Links Vitamin D and Autism
Dr. John Cannell of the Vitamin D Council published a 2008 paper establishing a link between low vitamin D levels and an increased prevalence of autism. In the paper, Cannell associates the rise in the prevalence of autism with increasing medical advice to avoid exposure to the sun in order to reduce skin cancer. Cannell notes that autism is more common in areas of low sunlight, such as northern parts of the country, urban communities, places with significant air pollution, and rainy regions. Several studies support these findings, including a recent Swedish study that found higher rates of autism in babies born in winter than in summer.
In January 2015, doctors in China reported that one autistic child there showed dramatic improvement of symptoms after receiving a monthly dosage of 150,000 IU in intramuscular injection and oral administration of 400 IU each day.
New Study Shows Vitamin D Supplementation Reduces Symptoms of Autism
The goal of the study was to evaluate the effects of vitamin D supplementation on the core symptoms of autism experienced by children.
The researchers entered 109 children into the double-blinded, randomized clinical trial. There were 85 boys and 24 girls enrolled in the study, all aged 3 to 10 years old. The scientists randomly assigned the participants either to a therapy group that received vitamin D3 supplements for four months or to the control group that received no supplements during the test period.
The scientists measured serum 25-hydroxycholecalciferol (25 (OH)D) levels at the beginning of the study and at the end. Also known simply as the 25-hydroxy vitamin D test, this common test is the most accurate method of determining how much vitamin D is in the body, according to the U.S. National Library of Medicine.
The researchers used double-blinded study, which means neither the participants nor the scientists knew which children were receiving vitamin D supplementation and which ones were in the control group. It was also a randomized clinical trial, meaning the researchers selected participants at random, and assigned the children to therapy and control groups randomly.
Children in the therapy group received daily doses of 300 IU vitamin D3/kg/day. The maximum dosage given to the children as 5,000 IU/day. This means the children received 300 IU of vitamin D3 daily for every kilogram of weight, which means a 35lb child would receive 4740 IU of vitamin D each day. This is significantly higher than the 600 IU per day recommended by the National Institutes of Health’s Office of Dietary Supplements for children between the ages of 1 and 13 years. The participants in the study tolerated supplementation of vitamin D well, however, despite the high dosage.
Using the assessment tests, the researchers were able to determine the symptoms of the children in the therapy group improved significantly after four months of vitamin D supplements, but the children in the placebo group did not improve.
The results of this study suggest that children with autism can benefit from high doses of vitamin D3 and can tolerate the treatment well.
This study was the first to evaluate the efficacy of vitamin D3 in patients with autism. The study was limited, though, in that it was a single trial using a small number of participants. To validate the use of vitamin D in children with autism requires additional wide-scale studies
Autism symptoms–such as hyperactivity, social withdrawal, and others–improved significantly following vitamin D3 supplementation but not after receiving placebo,? said Dr. Khaled Saad, lead author of the Journal of Child Psychology and Psychiatry study.
Check out our ASD condition spotlight section to find additional information.
According to the researchers, oral vitamin D supplementation may safely improve signs and symptoms of autism and could be recommended for children with the disorder, though a great deal more research is needed.