The effect of vitamin D and magnesium supplementation on the mental health status of attention-deficit hyperactive children: a randomized controlled trial

Randomized controlled trial in children with ADHD recruited from clinical settings in Isfahan, Iran. Participants were 6 to 12 years old and had low serum 25-hydroxyvitamin D and magnesium levels.

Children in the active arm received oral vitamin D 50,000 IU/week (pearl) with lunch plus oral magnesium 6 mg/kg/day (tablet) with lunch for 8 weeks, compared with placebo. The regimen was designed to correct low baseline vitamin D and magnesium status.

Vitamin D plus magnesium co-supplementation improved behavioral and mental health outcomes versus placebo over 8 weeks. SDQ scores favored the intervention group for emotional problems (p = 0.001), conduct problems (p = 0.002), peer problems (p = 0.001), prosocial score (p = 0.007), total difficulties (p = 0.001), externalizing (p = 0.001), and internalizing (p = 0.001). Reported effect sizes were moderate to large, including total difficulties (Cohen's d = -0.712) and internalizing (-0.855). Serum 25-OH-vitamin D and magnesium also increased significantly in the intervention group, and no adverse events were reported.

The intervention period was short at 8 weeks, and outcomes were limited mainly to SDQ scores and serum biomarkers. Baseline dietary intake of magnesium and vitamin D was not assessed, and physical activity data were not reported. The study was conducted in one city and clinic setting, which may limit generalizability.