Many families raising children with ADHD look for extra ways to support focus, behaviour, and emotional regulation. Medication does remain the most effective evidence-based treatment, however, research shows that some families do find that certain supplements can help, especially if a child has a nutritional deficiency. Supplements aren’t a cure, and they won’t necessarily work for everyone, but here’s what science says about the most commonly used supplements, what they can help with, and how long it usually takes to notice a difference.
Omega-3 (Fish Oil)
Omega-3 fatty acids (EPA and DHA) support brain cell communication and neurotransmitter function. Research consistently shows that children with ADHD tend to have lower omega-3 levels than their peers, and several reviews have found modest improvements in attention, cognitive efficiency, and behaviour when omega-3 supplements are used.
Many parents report better focus or calmer behaviour, while others notice no change. Capsules, liquids, or gummies can be used, and freezing capsules helps reduce the “fishy aftertaste.”
How long to try:
Most studies suggest that omega-3 needs 8–12 weeks before its benefits appear.
Magnesium
Magnesium deficiency is more common in children with ADHD and can contribute to hyperactivity, irritability, and sleep difficulties. Although magnesium does not directly improve attention, it may help children who struggle with:
• Afternoon “rebound” hyperactivity
• Anxiety or tension
• Difficulty falling asleep
Side effects mainly include diarrhoea or stomach discomfort.
How long to try:
Benefits are usually seen within 2-4 weeks, particularly for sleep and calming effects.
Zinc
Zinc plays a significant role in dopamine regulation, impulse control, and executive functioning. Children with ADHD are more likely to have lower zinc levels, and several studies, including a controlled trial showed improvements in hyperactivity and impulsivity when zinc was given, particularly in deficient children.
How long to try:
If a child is zinc-deficient, improvements may be seen within 6-8 weeks.
Iron (Ferritin)
Iron deficiency, especially low ferritin, is strongly associated with ADHD symptoms. One study found that 84% of children with ADHD had significantly low ferritin, compared with only 18% of children without ADHD. Low iron affects dopamine pathways and can worsen attention, restlessness, and fatigue.
How long to try:
When ferritin is low, progress usually appears after 8-12 weeks.
Vitamins B6 and B-Complex
Vitamin B6 is involved in neurotransmitter synthesis and fatty acid metabolism. Although research specifically linking B vitamins to ADHD symptom improvement is limited, some families report improvements in mood, energy levels, or mental clarity. B vitamins are generally low-risk and may support overall wellbeing.
How long to try:
If helpful, the changes are often noticed within 4-6 weeks.
Vitamin D
Vitamin D deficiency is common in children, including those with ADHD. While research has not yet confirmed that vitamin D supplementation directly improves ADHD symptoms, correcting a deficiency is important for overall physical health and may help support mood and behaviour.
How long to try:
Vitamin D levels are typically rechecked after 10-12 weeks of supplementation.
Final Advice for Parents
• Supplements should not replace prescribed medication, but they may support overall wellbeing or help soften afternoon “crashes.”
• If no benefit is seen after 2-3 months, it’s reasonable to stop.
• Choose reputable brands, as supplements are not tightly regulated.
• Monitor regularly for side effects such as stomach upset, diarrhoea, or constipation.
Supplements can play a supportive role for some children with ADHD, especially when addressing real deficiencies, but they tend to work best alongside evidence-based treatment, good sleep, balanced nutrition, and consistent behavioural strategies.
About the Author
Dr Hatem El-Emam is a GP with a special interest in ADHD. Coming from a Neurodiverse family, he is an advocate for early identification and management of ADHD. He firmly believes that with the correct understanding and proper support, ADHD energy and creativity can be turned into a strength.
References
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(2024). Vitamin D Guidelines. Children’s Wisconsin. https://childrenswi.org/-/media/chwlibrary/files/medical-care/clinical-nutrition/nutritionhandbook/vitamin_d_guidelines.pdf
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