17 Autism risk factors: low Vitamin D, virus, vaccine, mercury etc. - many studies
Low vitamin D, virus, vaccination, microplastics, Tylenol, gut bacteria, anti-biotics, Folic Acid,
transgender, extreme preterm birth, toxins, heavy metals, - - Most of which are fought by Vitamin D
Related in VitaminDWiki
Increased by: Vaccines, Virus, Toxins, Microplastics
Vaccines increase the risk of autism (25 studies) - Feb 2025
Aluminum increases Autism etc., silica decreases Aluminum - Dr. Coimbra video March 2025
Multiple Childhood Vaccinations increased autism risk by 4.4 X (Florida) – Jan 2025
Increased by: mother's obesity
Autism risk increased 2X by Obese mother, Even before Conception - Sept 2025
Increased by: Gut bacteria, Tylenol, Folic Acid, Antibiotics, Transgender
Aspartame while pregnant increased risk by 3.4 X that male infant will be Autistic – Sept 2023
Tylenol associated with both low vitamin D and Autism
- Quote from the internet: "A major problem with this theory is that in 1982, because of the cyanide poisoning scare, tylenol usage plummeted from 35% to only 8% and didn't recover to its previous high until about 2005. If Tylenol was a contributor to autism then we would've seen a drop in autism. But we didn't."
Transgender associated with autism, low vitamin D, low BMD, etc. - many studies
Increased / Decreased by some vitamins
Autism severity is associated with each of low Vitamins D, A, B-12 and E – Sept 2024
Autism 17 times more likely with excessive Folic Acid and B-12 (now added to bread) – May 2016
Decreased by: Vitamin D, etc.
Autistic measure 5X more likely if low vitamin D in second trimester – Oct 2012
Autism risk is reduced by Vitamin D – early pregnancy or chlldhood – Umbrella review – July 2024
Vitamin D fights autism - trying to figure out how and why – May 2022
Autism virtually non-existent if vitamin D levels greater than 44 ng while pregnant - Dec 2023
Autism associated with low Vitamin D (again) – Meta-Analysis Jan 2021
Autism severity is associated with each of low Vitamins D, A, B-12 and E – Sept 2024
24% lower risk of Autism for every 4 ng higher level of vitamin D during pregnancy – Feb 2024
Autism treated by Vitamin D (80 – 120 ng) – Cannell update May 2018 much more than the 30 ng required by bones
Autism may be worse if low in both Vitamin D and Vitamin A – Jan 2018
Autistic symptoms reduced by Vitamin D and or Omega-3 – RCT March 2019
Autism decreased in 8 out of 10 children supplemented with vitamin D – April 2015
Autism risk factors – many are associated with low vitamin D – meta-meta-analysis March 2017
Vitamin D and autism - treat: 300 IU per kg per day, prevent: during pregnancy 5,000 IU – Feb 2017
Autism 2X to 3X more likely if poor Vitamin D Receptor – June 2020
Autism treated by an activator of the Vitamin D Receptor: supforaphane - March 2024
Autism 1.75X more likely if BOTH maternal and infant vitamin D levels were low – Nov 2019
Autism risk increased 30 percent by Cesareans (both low vitamin D) – meta-analysis Sept 2019
Most Autism Risk factors are associated with low vitamin D - March 2014
25 reasons to associate Autism with low vitamin D - Dr. Cannell 2013
Both have strong inheritance features – Vitamin D about 60%
Both have gotten substantially worse in last 30 years
Vitamin D is known to be involved in brain development
All autistic children are VitD deficient, but not all children who are deficient are autistic: genes are involved
When giving vitamin D to cure children of rickets “mental dullness” decreases as well
Children with genes which give them too much (Williams Syndrome) have to reverse of autism – too sociable
Mothers having lots of fish (and thus more vitamin D) give birth to kids with less autistic symptoms
Both associated with weak bones
Both worse around the age of weaning
Autism is more common in rich families – more likely to apply sun screen and stay indoors
Autism increases with drugs which lower levels of vitamin D
Seizures are common with Autism - Vitamin D has been shown to reduce seizures
Fewer autistic symptoms (such as sleep problems) during summer: when child gets more vitamin D from the sun
Both worse with latitude
Both vary with Ultraviolet light
Both vary with time of year (more birth of autistics in March in Northern hemisphere)
2X more urban autism – less UVB in urban environments
Both worse with pollution
Both worse with increased clouds and rain
Both worse with closely spaced pregnancies
Autistics have abnormal immune response – similar to that of vitamin D deficiency
Low levels of vitamin D in mother animals reduces brain function in offspring
Vitamin D deficient rat pups have similar brain abnormalities to that of human autistic children
Autistic children get less vitamin D in their blood for the same amount of sun exposure
The 4 males/1 female ratio - Note estrogen increases vitamin D in the brain (testosterone does not)
Both worse in African Americans (A-A 2-3 increased autism rate)
Both worse in Dark-skinned immigrants in Europe
"Probably" no affect
Risk factors for Autism - hundreds of studies, and Dr. Roger's 2021 Dissertation on the factors - July 2025
Mapping autism causation studies, Part II July 2025
Tylenol and Autism - the appeals continue - Perplexity AI July 2025
📄 Perplexity PDF . No evidence - July 2023
Top 10 Risk factors by Perplexity AI - adds 5 more factors
| RISK | EVIDENCE | |
| 1. Genetic Factors/Heritability | PROVEN | |
| 2. Advanced Paternal Age | PROVEN | 600% if over 45 years old |
| 3. Advanced Maternal Age | PROVEN | 18% for every 10 years |
| 4. Low Birth Weight/Prematurity | PROVEN | 400% |
| 5. Gestational Diabetes/Maternal Diabetes | STRONG | ~50% |
| 6. Prenatal Valproate Exposure | STRONG | 520% |
| 7. Air Pollution Exposure During Pregnancy | STRONG | 46% per 10 micrograms PM2.5 |
| 8. Severe Maternal Infections During Pregnancy | MODERATE | 60% |
| 9. Prenatal Pesticide Exposure (Organophosphates) | MODERATE | 330% |
| 10. Cesarean Section Delivery | SUSPECTED | 33% |
URL = is.gd/autismfactors