Tourette syndrome is a condition where people experience involuntary movements and sounds called tics. Researchers found that people with Tourette syndrome often have low levels of vitamins A and D in their blood. In this study, scientists gave rats with tic-like symptoms either vitamin A or vitamin D for 8 weeks. The results showed that both vitamins significantly reduced the rats’ repetitive movements and twitching behaviors. The vitamins also changed the bacteria in the rats’ guts and affected brain chemicals related to movement control. While these findings are promising, more research is needed to understand exactly how these vitamins work and whether the same benefits apply to humans.

The Quick Take

  • What they studied: Whether giving vitamin A or vitamin D to rats with Tourette-like symptoms could reduce their involuntary movements and twitching behaviors
  • Who participated: Laboratory rats (10 total) that were given a chemical to create tic-like symptoms similar to Tourette syndrome in humans
  • Key finding: After 8 weeks of vitamin A or D treatment, rats showed significantly fewer tics and twitching movements compared to rats that didn’t receive the vitamins
  • What it means for you: This animal study suggests vitamins A and D might help reduce tics in people with Tourette syndrome, but human studies are needed before doctors can recommend this as a treatment. Talk to your doctor before starting any vitamin supplements.

The Research Details

Scientists used laboratory rats to study how vitamins A and D affect Tourette-like symptoms. First, they gave the rats a chemical called IDPN that causes involuntary movements similar to Tourette syndrome in humans. This chemical disrupts the normal balance of dopamine, a brain chemical that controls movement. Then, for 8 weeks, the researchers gave some rats vitamin A (3 mg per kilogram of body weight daily) and others vitamin D (10 micrograms per kilogram daily) through a feeding tube. The control group of rats received no vitamins. Throughout the study, researchers measured how often and how severe the rats’ involuntary movements were.

The scientists also collected blood samples to measure vitamin levels and checked the rats’ intestinal bacteria using genetic testing. They examined brain tissue to see how the vitamins affected important brain chemicals involved in movement control. This multi-pronged approach allowed them to look at how vitamins might work through different body systems—the brain, the blood, and the gut bacteria.

This research approach is important because Tourette syndrome is complex and involves multiple body systems working together. By studying both the brain chemicals and gut bacteria, researchers can understand whether vitamins help by working through the gut-brain connection. Animal studies like this are necessary first steps before testing treatments in humans, as they allow scientists to safely explore mechanisms and dosages.

This is a preliminary animal study with a small sample size (10 rats), which means the results are promising but not definitive. The study was well-designed with multiple measurements (behavior, blood work, brain chemistry, and gut bacteria), which strengthens the findings. However, animal studies don’t always translate directly to humans, so these results need to be confirmed in human clinical trials before drawing firm conclusions.

What the Results Show

The main finding was that both vitamin A and vitamin D significantly reduced tic-like behaviors in rats after 8 weeks of treatment. Rats receiving either vitamin showed noticeably fewer involuntary movements and head twitches compared to untreated rats. The improvement was statistically significant, meaning it was unlikely to have happened by chance.

Beyond just reducing visible tics, the vitamins also changed the levels of important brain chemicals (neurotransmitters) in the striatum, which is the brain region responsible for controlling movement. Vitamin A and D treatment normalized these chemical imbalances that were caused by the IDPN chemical.

Another important finding was that both vitamins changed the composition of bacteria living in the rats’ intestines. The diversity of gut bacteria increased, and the balance of different bacterial species shifted. This is significant because growing research suggests that gut bacteria communicate with the brain through what scientists call the “gut-brain axis.”

Blood tests showed that vitamin A and D supplementation successfully increased the levels of these vitamins in the rats’ bloodstreams. The vitamins also affected related blood minerals like calcium and phosphorus, and changed levels of alkaline phosphatase, an enzyme related to bone health. These changes suggest the vitamins were being absorbed and used by the body as intended.

Previous research had already shown that children with Tourette syndrome often have lower-than-normal levels of vitamin A (specifically retinoic acid) and vitamin D in their blood. Some smaller studies suggested that supplementing these vitamins might help reduce tic severity. This new rat study provides a biological explanation for why these vitamins might help—by affecting both brain chemistry and gut bacteria composition.

This study has several important limitations. First, it used only 10 rats, which is a very small sample size. Second, rats are not humans, and findings in animals don’t always work the same way in people. Third, the study used a chemical to artificially create tic-like symptoms, which may not perfectly mimic the complex causes of human Tourette syndrome. Fourth, the study didn’t directly prove that the gut bacteria changes caused the improvement in tics—it only showed that both happened together. Finally, the study didn’t compare vitamin A and D directly against each other or against current Tourette syndrome medications.

The Bottom Line

Based on this animal research, vitamin A and D supplementation appears promising for potentially reducing Tourette syndrome tics, but human clinical trials are needed before this can be recommended as a standard treatment. Current confidence level: Low to Moderate (this is preliminary animal research). Anyone with Tourette syndrome interested in trying vitamin supplements should discuss this with their neurologist or doctor first, as some vitamins can interact with medications or cause side effects at high doses.

This research is most relevant to people with Tourette syndrome and their families who are looking for additional treatment options beyond current medications. It may also interest healthcare providers treating Tourette syndrome. This research should NOT be used as a reason to stop taking prescribed medications without medical supervision. People with other conditions should not assume these vitamins will help their situation without consulting their doctor.

In this rat study, improvements were seen after 8 weeks of treatment. If similar benefits occur in humans, it might take several weeks to months to notice changes. However, individual responses vary, and human studies would need to confirm whether the same timeline applies.

Want to Apply This Research?

  • If working with a doctor to try vitamin A and D supplementation, track tic frequency daily by counting the number of involuntary movements or vocalizations during a set 10-minute period at the same time each day. Record this in a simple log to show your doctor how symptoms change over weeks.
  • Work with your healthcare provider to establish a consistent daily vitamin supplementation routine at the same time each day. Use app reminders to take supplements and log them, creating accountability and ensuring consistent dosing.
  • Create a weekly summary of tic severity (mild, moderate, severe) and overall quality of life. Track any side effects or changes in other symptoms. Share this data with your doctor monthly to assess whether the supplementation is helping and whether adjustments are needed.

This research is a preliminary animal study and should not be used to self-treat Tourette syndrome or any other condition. Vitamin A and D supplements can cause side effects and interact with medications at high doses. Anyone with Tourette syndrome considering vitamin supplementation must consult with their neurologist or healthcare provider before starting any new supplements. This study does not replace professional medical advice, diagnosis, or treatment. Always work with qualified healthcare professionals before making changes to your treatment plan.