Researchers looked at dozens of studies to see if vitamin supplements could help children with autism and ADHD. They found that taking certain vitamins may help reduce symptoms in both conditions, but different vitamins work better for different disorders. Vitamin B supplements appeared most helpful for autism symptoms, while vitamin D seemed to work better for ADHD. The good news is that vitamins are affordable and easy to access, making them a practical option to explore alongside other treatments. However, scientists say more research is needed to understand exactly how much of each vitamin helps and which children benefit most.

The Quick Take

  • What they studied: Whether taking vitamin supplements could reduce symptoms in children and adults with autism spectrum disorder (ASD) or attention-deficit/hyperactivity disorder (ADHD)
  • Who participated: The researchers reviewed multiple studies involving people with ASD and ADHD of various ages. The exact total number of participants wasn’t specified, but they analyzed data from many different research projects published in medical databases
  • Key finding: Vitamin supplements showed promise in reducing symptoms for both conditions, with vitamin B being particularly helpful for autism and vitamin D being more effective for ADHD. However, the strength of these effects varied across different studies
  • What it means for you: If you or a family member has autism or ADHD, talking to a doctor about vitamin supplements may be worth exploring as part of a treatment plan. However, vitamins should not replace other proven treatments, and it’s important to get professional guidance on which vitamins and doses are right for your situation

The Research Details

This was a meta-analysis, which means researchers searched through published studies from major medical databases (PubMed, Web of Science, and Cochrane Library) to find all available research on vitamin supplements for autism and ADHD. They then combined the results from multiple studies to see if there were patterns in how vitamins affected symptoms.

The researchers focused on studies that tested different types of vitamins—like B vitamins, vitamin D, and others—in people diagnosed with autism or ADHD. They looked at how these supplements affected both the main symptoms of these conditions and related problems like digestive issues (constipation is common in both autism and ADHD).

By combining data from many studies, the researchers could get a clearer picture than any single study could provide. This approach helps identify which vitamins seem most promising and which conditions they help the most.

A meta-analysis is valuable because individual studies can sometimes give conflicting results or involve small groups of people. By looking at many studies together, researchers can see the bigger picture and identify real patterns. This approach is especially important for understanding whether vitamins actually help, since some studies might show benefits while others don’t. Combining all the evidence helps separate what really works from what might just be coincidence.

This study was published in a peer-reviewed medical journal, meaning other experts reviewed it before publication. The researchers used established medical databases to find studies, which is the standard approach. However, the quality of the findings depends on the quality of the original studies included in the analysis. The researchers noted that most existing studies compare people with autism or ADHD to healthy people, rather than testing whether vitamins actually improve symptoms in people with these conditions. This is an important limitation that affects how confident we can be in the results.

What the Results Show

The analysis found that vitamin supplements appeared to reduce symptoms in both autism and ADHD, which is encouraging news. However, the effects were not the same for all vitamins or all conditions.

For autism spectrum disorder, vitamin B supplements showed the strongest benefits. B vitamins include several types (like B6, B12, and folate) that help the brain and nervous system work properly. The research suggests these vitamins may help with core autism symptoms, though the exact reasons why aren’t completely understood yet.

For ADHD, vitamin D supplements appeared to be more effective than other vitamins. Vitamin D is sometimes called the “sunshine vitamin” because our bodies make it when exposed to sunlight. It plays important roles in brain function and mood regulation, which may explain why it seemed to help ADHD symptoms more than other vitamins.

The researchers also noted that vitamins appeared helpful for digestive problems like constipation, which are common in both conditions. This is particularly important because digestive issues can make other symptoms worse and affect quality of life.

Beyond the main findings, the research suggests that different vitamins may work through different mechanisms in the body. This means that vitamin B and vitamin D might help symptoms in different ways, rather than all vitamins working the same way. The findings also indicate that a one-size-fits-all approach to vitamin supplementation probably won’t work—what helps one person might not help another, depending on which condition they have and their individual body chemistry.

This research builds on growing interest in using vitamins as a complementary approach to managing autism and ADHD. Previous studies have suggested that some people with these conditions may have vitamin deficiencies, which could contribute to symptoms. This meta-analysis strengthens that evidence by showing that supplementing these vitamins may actually improve how people feel and function. However, the researchers noted that most previous studies compared people with autism or ADHD to healthy people, rather than testing whether vitamins actually help people with these conditions get better. This new analysis helps fill that gap.

The researchers identified several important limitations. First, they didn’t specify exactly how many people were included across all the studies they reviewed, making it harder to understand the strength of the evidence. Second, the original studies varied widely in their methods, vitamin types, doses, and how they measured improvements, which makes it harder to draw firm conclusions. Third, most studies compared people with these conditions to healthy controls rather than testing whether vitamins actually improved symptoms over time. Finally, the research didn’t clearly identify which specific people benefit most from vitamin supplements, so it’s unclear whether all individuals with autism or ADHD should try them or only certain subgroups.

The Bottom Line

Based on this research, it may be reasonable to discuss vitamin supplementation with a healthcare provider if you have autism or ADHD, particularly vitamin B for autism or vitamin D for ADHD. However, confidence in these recommendations is moderate—the research is promising but not definitive. Vitamins should be considered as part of a comprehensive treatment plan, not as a replacement for established treatments like therapy or medication. Always consult with a doctor before starting any supplement, as vitamins can interact with medications and aren’t appropriate for everyone.

This research is relevant for people with autism or ADHD, their families, and healthcare providers looking for additional treatment options. It may be particularly interesting for those seeking affordable, accessible approaches to managing symptoms. However, people with certain medical conditions, those taking specific medications, or those with vitamin absorption problems should be especially careful to get professional medical advice before supplementing. Pregnant or breastfeeding women should also consult their doctors before taking supplements.

If vitamins do help, benefits are unlikely to appear immediately. Most research suggests it takes several weeks to a few months of consistent supplementation to notice changes in symptoms. Some people may see improvements in digestive symptoms faster than improvements in core autism or ADHD symptoms. It’s important to have realistic expectations and give any supplement adequate time before deciding whether it’s working.

Want to Apply This Research?

  • Track daily vitamin intake and rate core symptoms (focus, attention, mood, digestive comfort) on a simple 1-10 scale each evening. Record any changes in behavior, energy levels, or symptom severity over 8-12 weeks to see if patterns emerge
  • Set a daily reminder to take your vitamin supplement at the same time each day (ideally with food if recommended). Use the app to log which vitamin you’re taking, the dose, and any side effects or improvements you notice
  • Create a weekly summary view showing your symptom ratings over time alongside your supplement adherence. Share this data with your healthcare provider at regular check-ins to help determine if the vitamin is actually helping your specific situation

This research summary is for educational purposes only and should not replace professional medical advice. Vitamin supplements can interact with medications and may not be appropriate for everyone. Before starting any vitamin supplement, especially for a child or if you have other health conditions, consult with a qualified healthcare provider. This meta-analysis shows promising results but is not definitive proof that vitamins will help your specific situation. Individual responses to supplements vary greatly, and what works for one person may not work for another. Always inform your doctor about any supplements you’re considering or taking.