Zinc, iron, vitamin C, vitamin B6, and magnesium are particularly helpful for focus and attention. Some studies have shown that taking zinc supplements can help reduce hyperactivity and impulsivity for children with ADHD. Iron is another nutrient that improves focus. Just be careful to provide your child with the appropriate dosage so that they do not have too much. Vitamin C is used to make neurotransmitters like dopamine and norepinephrine. Children who are low in vitamin B6 can show signs of fatigue and irritability which can cause difficult with focus. Making sure that your child has sufficient B6 can help them improve their alertness. Magnesium has a calming effect on the brain which helps reduce hyperactivity and increase attention.