New research indicates causal link between vitamin D, serotonin synthesis and autism

A new study by Rhonda Patrick, PhD and Bruce Ames, PhD of Children's Hospital Oakland Research Institute (CHORI) demonstrates the impact that Vitamin D may have on social behavior associated with Autism Spectrum Disorder (ASD). Dr. Patrick and Dr. Ames show that serotonin, oxytocin, and vasopressin, three brain hormones that affect social behavior, are all activated by vitamin D hormone. Autism, which is characterized by abnormal social behavior, has previously been linked to low levels of serotonin in the brain and to low vitamin D levels, but no mechanism has linked the two until now.

In this study, Dr. Patrick and Dr. Ames show that vitamin D hormone activates the gene that makes the enzyme tryptophan hydroxylase 2 (TPH2), that converts the essential amino acid tryptophan, to in the . This suggests that adequate levels of vitamin D may be required to produce serotonin in the brain where it shapes the structure and wiring of the brain, acts as a neurotransmitter, and affects . They also found evidence that the gene that makes the enzyme tryptophan hydroxylase 1 (TPH1) is inhibited by vitamin D hormone, which subsequently halts the production of serotonin in the gut and other tissues, where when found in excess it promotes inflammation.

This mechanism explains many of the known, but previously not understood, facts about autism including: 1) the "serotonin anomaly" low levels of serotonin in the brain and high levels in the blood of ; 2) the preponderance of male over female autistic children: estrogen, a similar steroid hormone, can also boost the brain levels of serotonin in girls; 3) the presence of autoimmune antibodies to the fetal brain in the mothers of autistic children: vitamin D regulates the production of regulatory T-cells via repression of TPH1. The Patrick/Ames mechanism is relevant to the prevention of autism, and likely its treatment.

The current guidelines for adequate vitamin D levels are concentrations above 30 ng/ml. Most Americans' vitamin D is made in the skin from exposure to UVB radiation; however, melanin pigment and sunscreen inhibit this action. This is an important cause of the well-known widespread vitamin D deficiency among dark-pigmented Americans, particularly those living in Northern latitudes. The most recent National Health and Examination survey reports that greater than 70% of U.S. population does not meet this requirement and that adequate vitamin D levels have plummeted over the last couple of decades. This precipitous drop in adequate levels of vitamin D in the US is concurrent with the rise in autism rates.

The study suggests dietary intervention with vitamin D, tryptophan and omega 3 fatty acids would boost brain serotonin concentrations and help prevent and possibly ameliorate some of the symptoms associated with ASD without side effects. There is little vitamin D present in food and fortification is still inadequate as is the amount in most multivitamin and prenatal supplements. Vitamin D supplements are inexpensive and offer a simple solution to raise vitamin D levels to an adequate status. In addition, vitamin D levels should be routinely measured in everyone and should become a standard procedure in prenatal care.

Provided by Children's Hospital & Research Center Oakland

4.9 /5 (11 votes)
add to favorites email to friend print save as pdf

Related Stories

Vitamin D deficiency may compromise immune function

Feb 25, 2014

Older individuals who are vitamin D deficient also tend to have compromised immune function, according to new research accepted for publication in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM) ...

Low vitamin D causes brain damage

Dec 02, 2013

A new study led by University of Kentucky researchers suggests that a diet low in vitamin D causes damage to the brain.

Can citrus ward off your risk of stroke?

Feb 14, 2014

Eating foods that contain vitamin C may reduce your risk of the most common type of hemorrhagic stroke, according to a study released today that will be presented at the American Academy of Neurology's 66th Annual Meeting ...

Recommended for you

Why do people with autism see faces differently?

22 hours ago

The way people with autism spectrum disorder (ASD) gather information - not the judgement process itself - might explain why they gain different perceptions from peoples' faces, according to a new study from ...

How does the brain develop in individuals with autism?

Nov 12, 2014

Geneticists at Heidelberg University Hospital's Department of Molecular Human Genetics have used a new mouse model to demonstrate the way a certain genetic mutation is linked to a type of autism in humans and affects brain ...

User comments

Adjust slider to filter visible comments by rank

Display comments: newest first

JVK
1 / 5 (1) Feb 26, 2014
"Labeling the majority of the black participants as vitamin D–deficient would be inconsistent with the observation that they had higher BMD, higher calcium levels, and only slightly higher parathyroid hormone levels than their white counterparts."

Vitamin D–Binding Protein and Vitamin D Status of Black Americans and White Americans
http://www.nejm.o...a1306357
Seth Bittker
not rated yet Mar 01, 2014
This is an interesting study. Babies receive signficantly more vitamin D orally than they did in the 1980s through fortification and supplementation. Yet the autism rate has increased substantially since then.

This is just one piece of evidence that vitamin D supplementation is not warranted in most cases of autism. There is a lot of other evidence for the hypothesis that supplementation with vitamin D is a risk factor for inducing autism. Here is a journal article that I am the author of that explores this: http://www.omicsg...0125.pdf

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.