Autism spectrum disorder (ASD) is a neurological and developmental condition that affects 1 in 44 children in the United States alone. Although there is not one particular vitamin deficiency that directly causes autism, there may be some maternal vitamin deficiencies that are linked with an increased risk of children developing ASD. Read on to learn more about these potential risk factors and how vitamin deficiencies can affect individuals with ASD throughout their lives.

Causes of Autism

At this time, there is no single known cause of autism. It is an extremely complex disorder with varying severity and symptoms from case to case, so there are likely a number of different factors that can contribute to its development. For some children, genetics may play a role in their development of ASD, including genetic disorders like fragile X syndrome or Rett syndrome or genetic changes that could affect brain development (1). The most likely cause is an interaction between these genetic changes and certain environmental factors. Research has found that the following environmental factors during or after birth, when paired with certain genetic changes, could place a child at higher risk of developing ASD: exposure to air pollution or pesticides, extremely low birth weight or prematurity, advanced age of parents at conception, and maternal immune system disorders, obesity, or diabetes (2).

Another factor that may increase a child’s risk of developing ASD is biological sex. Children who are assigned male at birth (AMAB) are about 4 times more likely to be diagnosed with ASD than those assigned female at birth (AFAB) (3). The exact cause of this difference is unknown, but one possible explanation may be variations in the way boys and girls present symptoms, leading to a rate of underdiagnosis in females. Another possibility may be that females require more genetic changes than males in order to develop the disorder (4). In either case, however, biological sex is still not the main cause of ASD and may or may not contribute to its overall risk factors.

The Risks of Vitamin D Deficiency

As we explained, there are no distinct singular causes for autism. However, there is some evidence to indicate a potential link between vitamin D deficiency in mothers and the development of ASD in children. In these cases, vitamin D deficiency was possibly a contributing factor to nervous system abnormalities associated with ASD (5). One animal study in particular found that vitamin D deficiency may even be part of the reason why ASD is more likely to develop in males. Researchers discovered that low levels of vitamin D in mothers could result in increased amounts of testosterone in male brains during pregnancy (6). Overexposure to sex hormones during brain development may be a possible cause of ASD, though the results are still inconclusive at the moment.

If the results in these studies are true, then mothers who fear their children could be at an increased risk for ASD may want to speak with their physician about vitamin D deficiency. Unlike other vitamins, vitamin D is produced by your skin when it comes in contact with sunlight rather than being absorbed from your diet. For this reason, those who are unable to spend much time outside could be at an increased risk for deficiency. Supplementation is a possible solution, with many multivitamins including vitamin D in their ingredients. You may also be able to increase your vitamin D intake by eating fortified foods like milk or cereal. Just remember to be cautious and communicate with your doctor, especially when taking a supplement during pregnancy.

Multivitamins for Autism

Individuals with autism may be at an increased risk of developing nutrient deficiencies due to differences in eating habits and preferences. In this case, it may be helpful to provide a multivitamin that helps fill in any nutritional gaps that could form as a result of these differences. In addition to the usual essential vitamins and minerals, there are various nutrients to look for in particular when it comes to the best liquid multivitamin for autism, including vitamins B12 and D and the macromineral magnesium. Below, we have provided a quick rundown of how each of these nutrients could benefit individuals with ASD:

• Vitamin B12: May improve various forms of communication in ASD patients, including receptive, expressive, and written language (7).
• Vitamin D: May improve ASD symptoms associated with stimming, communication, and social interaction (8).
• Magnesium: May improve ASD symptoms associated with hyperactivity, restlessness, fidgeting, poor concentration, and noise sensitivity (9).

Resources

1. Mayo Clinic Staff. “Autism Spectrum Disorder.” Mayo Clinic, 6 January 2018, https://www.mayoclinic.org/diseases-conditions/autism-spectrum-disorder/symptoms-causes/syc-20352928.
2. “Autism.” National Institute of Environmental Health Sciences, 30 August 2021, https://www.niehs.nih.gov/health/topics/conditions/autism/index.cfm.
3. “Autism Statistics and Facts.” Autism Speaks, 2022, https://www.autismspeaks.org/autism-statistics-asd.
4. Zeliadt, Nicholette. “Autism’s Sex Ratio, Explained.” Spectrum, 13 June 2018, https://www.spectrumnews.org/news/autisms-sex-ratio-explained.
5. Principi, Nicola and Susanna Esposito. “Vitamin D Deficiency During Pregnancy and Autism Spectrum Disorders Development.” Frontiers in Psychiatry, 31 January 2020, https://www.frontiersin.org/articles/10.3389/fpsyt.2019.00987/full.
6. Henderson, Emily. “Vitamin D Deficiency Could Explain Why Autism Spectrum Disorder Is More Common in Boys.” News-Medical, 11 December 2020, https://www.news-medical.net/news/20201211/Vitamin-D-deficiency-could-explain-why-autism-spectrum-disorder-is-more-common-in-boys.aspx.
7. Van Der Laan, Joya. “Supplements for Speech Delays in Autistic Children.” Your Autism Game Plan, 11 October 2021, https://yourautismgameplan.com/supplements-for-speech-delays-in-autistic-children.
8. Saad, Khaled et al. “Randomized Controlled Trial of Vitamin D Supplementation in Children with Autism Spectrum Disorder.” Journal of Child Psychology and Psychiatry, January 2018, https://pubmed.ncbi.nlm.nih.gov/27868194.
9. Markham Integrative. “The Importance of Magnesium in Autism & ADHD.” Markham Integrative Medicine, 9 March 2017, https://integrative-medicine.ca/the-importance-of-magnesium-in-autism-adhd.