Abstract
Objective: We investigated whether changes in serum nutrient levels mediate clinical response to a micronutrient intervention for ADHD. Method: Data were compiled from two ADHD trials (8-10 weeks), one in adults (n = 53) and one in children (n = 38). Seven outcomes included change in ADHD symptoms, mood, overall functioning (all clinician-rated) as well as response status. Change in serum/plasma nutrient levels (vitamins B-12 and D, folate, ferritin, iron, zinc, and copper) were considered putative mediators. Results: A decrease in ferritin and an increase in copper were weakly associated with greater likelihood of being identified as an ADHD responder; none of the other nutrient biomarkers served as mediators. Conclusion: Further research looking at nutrients more broadly from other tissues are required to confirm these initial observations of the limited value of nutrient levels in deciphering mechanism of action. Monitoring these biomarkers on their own is unlikely helpful in understanding clinical response to a broad-spectrum micronutrient approach.