Vitamin D, Iron Balanced With 500 mL Milk/Day for Children
(HealthDay News) – Two cups of cow's milk per day is sufficient to maintain healthy vitamin D and iron stores for most young children, according to a study published online Dec. 17 in Pediatrics.
Jonathon L. Maguire, MD, from the University of Toronto, and colleagues used parental reports to measure cow's milk intake in 1,311 healthy children ages 2–5 years. Serum 25-hydroxyvitamin D and ferritin were used to measure stores of vitamin D and iron.
The researchers found that increasing cow's milk consumption was significantly associated with decreasing serum ferritin and increasing 25-hydroxyvitamin D. For most children, two cups of cow's milk per day maintained 25-hydroxyvitamin D >75nmol/L with minimal negative effect on serum ferritin. Three to four cups of cow's milk per day was needed for children with darker skin pigmentation not receiving vitamin D supplementation during the winter in order to maintain 25-hydroxyvitamin D >75nmol/L. Among children using a bottle, cow's milk intake did not increase 25-hydroxyvitamin D and resulted in more dramatic decreases in serum ferritin.
"Our findings suggest that there is a trade-off between increasing 25-hydroxyvitamin D and decreasing serum ferritin with increasing milk intake," the authors write. "For most children, two cups (500mL) of cow's milk per day was sufficient to maintain healthy vitamin D stores with minimal impact on serum ferritin."