Summary:
Neurodevelopmental conditions arise early in life and shape thinking, behaviour, and learning. Autism, ADHD, intellectual disability, Down syndrome, and epilepsy each present different developmental profiles but share several features. Together they affect between 0.5-5% of the population. Most conditions persist across the lifespan, although epilepsy may remit in some individuals. Their origins lie in prenatal development, influenced by genetics, however their exact origins remains only partly understood. Standard behavioural and pharmacological treatments provide essential support, but their limitations have increased interest in approaches such as nutrition. This study is a narrative review that examined nutritional factors across autism, ADHD, Down syndrome, intellectual disability, and epilepsy. The evidence shows that nutrient deficiencies, selective eating, gastrointestinal issues, and metabolic differences are common. In autism, vitamin D supplementation reduces inflammatory markers and is associated with behavioural improvements. In ADHD, vitamin D combined with magnesium improves behaviour. In epilepsy, ketogenic diets consistently reduce seizures, whereas vitamin D and omega‑3 fatty acids show minimal benefit. Down syndrome studies report gains in communication and motor development following combined supplementation with vitamin D, DHA, and L‑carnosine . Adults with intellectual disability show extremely high rates of vitamin D deficiency. Overall, the evidence indicates that nutritional status interacts closely with neurodevelopmental conditions. Deficiencies in vitamin D, omega‑3 fatty acids, and minerals such as iron, zinc, and magnesium may worsen neuroinflammation and oxidative stress. Correcting these deficits can support improvements in behaviour, attention, adaptive functioning, and motor development. This study concludes that nutrition is a central component of neurodevelopmental conditions and that future work should prioritise nutrition based approaches.
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Abstract:
Neurodevelopmental disorders including Autism Spectrum Disorder (ASD), Attention-Deficit/Hyperactivity Disorder (ADHD), Down syndrome (DS), intellectual disability (ID), and epilepsy are associated with overlapping behavioural, metabolic, and neurobiological vulnerabilities that influence nutritional status. Across conditions, consistent deficiencies in vitamin D, omega-3 fatty acids, and key micronutrients such as iron, zinc, magnesium, and B-vitamins are frequently reported, contributing to shared mechanisms of neuroinflammation, oxidative stress, mitochondrial dysfunction, impaired neurotransmitter synthesis, and gut brain axis disruption. Clinical evidence indicates that vitamin D demonstrates the most robust cross condition benefits, improving neuroimmune regulation, serotonergic pathways, and motor and cognitive outcomes. Omega-3 fatty acids support synaptic function, membrane stability, and anti-inflammatory lipid mediator production, while multi micronutrient formulations enhance one carbon metabolism, mitochondrial energy generation, and antioxidant defence. In epilepsy, ketogenic dietary therapies exert neuroprotective and antiseizure effects through ketone-driven modulation of GABAergic signalling, mitochondrial efficiency, and reduced neuronal excitability. Despite nutritional vulnerabilities, neurodivergent individuals exhibit significant strengths, including enhanced pattern recognition, visual spatial reasoning, creativity, persistence, and distinctive problem solving approaches. Recognizing these strengths is essential to delivering person-centred nutritional and therapeutic interventions. Overall, current clinical and mechanistic evidence demonstrates that nutrition is a meaningful modifiable factor shaping neurodevelopmental trajectories. Integrating systematic nutritional assessment with individualized interventions may optimize behavioural, developmental, and functional outcomes, while future research should prioritize biomarker-guided precision nutrition strategies to refine therapeutic applications across neurodevelopmental conditions.
Article Publication Date: 13/02/2026
DOI: 10.1007/s44187-026-00804-4
