Studies suggest kids with autism may have lower vitamin-D levels
What's the story
As cases of autism continue to rise worldwide, scientists are looking at every possible factor, including nutrition. One such nutrient is vitamin D, with recent studies indicating a potential link between its deficiency and the risk of autism in children. A comprehensive review of several studies has found that children with Autism Spectrum Disorder (ASD) often have significantly lower levels of vitamin D than their neurotypical peers.
Deficiency impact
Rising autism diagnoses and declining vitamin D levels
The discovery of low vitamin D levels in children with ASD has sparked speculation about the role of vitamin D deficiency, especially during early development, in the rising number of autism cases. Global estimates indicate that autism diagnoses have skyrocketed over recent decades. While some of this increase can be attributed to improved awareness and diagnosis, experts also point to environmental and lifestyle factors as contributing elements.
Research findings
Review found children with ASD have lower vitamin D levels
A recent umbrella review analyzing nine meta-analyses and systematic reviews found that children with ASD have lower levels of 25-hydroxyvitamin D [25(OH)D], the primary circulating form of vitamin D. The review also found a link between early-life vitamin D deficiency and an increased risk of developing autism. Interestingly, it also noted that supplementation showed positive effects on some autism symptoms such as repetitive behaviors, eye contact, and attention span.
Development support
How vitamin D may influence brain development
Vitamin D is believed to aid brain development in several ways, including reducing inflammation, boosting antioxidant levels (like glutathione), supporting nerve cell growth, and regulating serotonin, a key brain chemical linked to mood and behavior. It may also reduce autoimmune and oxidative stress, both of which are thought to contribute to ASD. In one clinical trial, high-dose vitamin D supplements were given to children with autism for four months, with promising results.
Research gap
Need for caution and more research
Not all studies have yielded consistent results, owing to variations in dosages, study durations, and small sample sizes. Experts agree that larger, well-designed clinical trials are needed to determine the optimal dosing, timing, and long-term safety of vitamin D for children with autism. Health professionals are encouraged to screen children with autism for vitamin D deficiency, especially those who get little sun exposure or have restrictive diets, and consider high-dose supplementation protocols under medical guidance if needed.