More and more families face the heartache and sleepless nights of raising a child that does not really fit into the world. Currently, 1 in 88 children in the U.S. have autism and the prevalence is rapidly increasing without a clear cause. Studies show that the neurotransmitter, serotonin, is unbalanced in autistic children. More specifically, autistic children have more serotonin in the body but less serotonin in the brain also known as serotonin anomaly. Since serotonin in the brain is involved in social networks, lacking this important chemical creates impairment in social behaviour.

But what is the cause of this unbalance? A recent study from Patrick and Ames from the Children’s Hospital Oakland Research Institute suggests that the sunshine vitamin, vitamin D, may contribute to the unbalanced serotonin synthesis and in turn cause autism. This essential vitamin is synthesized in our body when we spend time in the sun but can also come from daily food such as fish, mushroom, soy and eggs. Vitamin D is able to activate or deactivate gene encoding and it is known to regulate approximately 900 different genes, many of which impact brain function and development.

To understand how this works we need to direct the attention to the synthesis of serotonin. Serotonin is synthesized from the precursor tryptophan by the enzyme tryptophan hydroxylase (TPH). Since serotonin cannot cross the blood brain barrier, the enzyme is present in two versions: TPH1 in the body and TPH2 in the brain. Vitamin D is able to activate or repress TPH transcription and interestingly enough this can only occur for one enzyme at a time while the other enzyme is repressed. In the case of low vitamin D, the TPH1 in the body is activated while the TPH2 in the brain is repressed and consequently, more serotonin in the body and less serotonin in the brain explaining the phenomenon of serotonin anomaly in autism.

Unfortunately nowadays our lives are becoming an indoor activity and many people worldwide have vitamin D deficiency, which is known to be correlated with the high autism incidence. Therefore it is essential to have a sufficient amount of vitamin D, especially for pregnant woman, to keep the serotonin production on track and to help shape the foetal brain accordingly. To conclude, getting vitamin D through sunshine may be a simple method of increasing serotonin and to help prevent autism. So go outside and get some sun!