3. Vitamin D Keeps Gut Serotonin in Check
What Patrick discovered is that, in the gut, vitamin D turns off, or dampens the activity of the gene responsible for making the enzyme that converts tryptophan into serotonin. In this way, vitamin D helps combat inflammation in your gut caused by excessive serotonin levels.
In the brain, the tryptophan hydroxylase gene has a sequence that causes the opposite reaction. Here vitamin D activates the gene, thereby increasing serotonin production! Needless to say, when you have sufficient amounts of vitamin D, two things then happen simultaneously:
- Gut inflammation is reduced, courtesy of deactivating the gene associated with serotonin production
- Serotonin levels in the brain are increased by gene activation, and in the brain, serotonin plays an important role in mood, impulse control, long-term planning, long-term behavior, anxiety, memory, and many other cognitive functions and behaviors, including sensory gating — the ability to filter out extraneous or unimportant stimuli
Since the publication of Patrick’s first paper4 in 2014, an independent group at the University of Arizona has biochemically validated her findings,5 confirming that vitamin D does activate the tryptophan hydroxylase 2 (TPH2) gene in a variety of neuronal cell types.
Prior to the publication of that paper, this simply wasn’t known, and it’s a significant finding that can help shed a great deal of light on vitamin D’s influence in autism, as a majority of autistic kids have not only brain dysfunction, but also gut inflammation. Her research shows quite clearly how important it is to have enough vitamin D to prevent and treat both of these problems.
The Role of Serotonin During Early Brain Development
During the fetal brain development phase, serotonin plays an important role in brain morphogenesis. Simply put, serotonin is an ingredient required for the development of the brain’s shape, structure, and internal wiring. Serotonin basically tells the neurons where to position themselves in the brain, and what type of neurons they should become. If you don’t have sufficient amounts of serotonin, abnormal brain structure and brain wiring will result.
“In mouse models, it’s been shown to lead to the mouse equivalent of autistic behaviors,” Dr. Patrick notes. “Serotonin plays a very important role in brain development. What’s really interesting is that the developing fetus depends entirely on the mother’s levels of vitamin D.
The vitamin D from the mother crosses over the placenta, gets into the blood-brain barrier, gets into the fetal brain, and activates all those fetal genes.
If a mother is deficient in vitamin D, this may have severe consequences in the developing fetal brain of her child, because maybe that gene that needs vitamin D to get activated is not getting activated. As a consequence, there’s not enough serotonin being made in the fetal brain, which possibly could affect the way that brain develops…
Vitamin D and low serotonin have been linked to autism by many different researchers. But no one has put the two together as a mechanism going, ‘Look, maybe the low vitamin D leads to low serotonin in the developing brain. This may be part of the reason why there’s an increase in autism, and maybe part of the way why low vitamin D leads to autism.'”
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