Unleashing children’s potential: An evidence-based narrative review of strategies to enhance cognitive function and intelligence in school-age children

Table 4 Key micronutrients, neurobiological mechanisms, cognitive domains, and strength of evidence in school-age children

Micronutrient	Primary neurobiological mechanisms	Key cognitive domains affected	Evidence strength1	Recommended daily intake (6-12 yrs)
Iron	Oxygen transport and cerebral energy metabolism. Myelination of white matter tracts. Dopaminergic neurotransmission	Attention, working memory, processing speed, and learning efficiency	High (consistent longitudinal data; RCT benefit in deficient children)	10-12 mg/day
Iodine	Thyroid hormone synthesis. Regulation of neuronal metabolism and synaptic plasticity	Verbal intelligence, reasoning, EF	Moderate-high (strong biological plausibility; RCTs mainly in deficient regions)	120 μg/day
Zinc	Synaptic signaling and neurogenesis. Modulation of glutamate and GABA receptors	Attention, memory, EF	Moderate (context-dependent; strongest effects in deficient/malnourished populations)	8-10 mg/day
Vitamin D	Neuroimmune regulation. Neurotransmission and neurotrophic signaling	EF, attention, and processing speed	Low-moderate (observational consistency; mixed RCT results)	600 IU/day (15 μg)
Folate (B9)	One-carbon metabolism. DNA methylation and neurotransmitter synthesis	Attention, memory, and academic achievement	Moderate (longitudinal support; limited school-age RCTs)	300 μg/day (dietary folate equivalents)
Vitamin B12	Myelin synthesis. Neuronal integrity and energy metabolism	Memory, processing speed, EF	Moderate (strong mechanistic rationale; limited intervention trials)	1.8-2.4 μg/day
Vitamin B6	Synthesis of serotonin, dopamine, and GABA	Attention regulation, EF	Low-moderate (supportive mechanistic data; limited direct cognitive trials)	1.0-1.3 mg/day
Choline	Acetylcholine synthesis. Cell membrane formation and signaling	Memory, learning, EF	Low-moderate (emerging evidence; paucity of RCTs in school-age children)	375-400 mg/day
Vitamin C	Antioxidant defense; catecholamine synthesis; synaptic plasticity	Attention, learning, and processing speed	Moderate (cohort + mechanistic)	45-75 mg/day (children-adolescents)
Vitamin E	Membrane protection; prevention of lipid peroxidation; synaptic integrity	Memory, EF	Moderate (cohort + biological plausibility)	7-15 mg/day (α-tocopherol equivalents)

¹Evidence strength reflects consistency across randomized controlled trials, longitudinal cohort studies, and mechanistic plausibility in school-age populations (6-12 years). Cognitive benefits of supplementation are most consistently observed in children with documented deficiency or inadequate dietary intake. Upper intake limits should be respected; routine high-dose supplementation is not recommended without clinical indication.

EF: Executive function; GABA: Gamma-aminobutyric acid; RCTs: Randomized controlled trials.