The Effect of Milk Intake on Vitamin D and Iron Levels in Children

Consuming 2 cups of milk per day is sufficient to maintain healthy vitamin D levels without depleting iron levels for most children at northern latitudes.

Cow's milk consumption increases vitamin D levels; however, cow's milk can deplete iron stores in young children. The amount of intake required for sufficient stores of vitamin D and iron is poorly understood. Investigators recruited healthy children aged 2 to 5 years through a primary care practice research network in Toronto, Canada, over a 2-year period. They performed a cross-sectional analysis of the relationship between cow's milk and stores of vitamin D and iron. Cow's milk intake was assessed based on parental report. Serum 25-hydroxyvitamin D and ferritin levels were measured, and skin pigmentation, vitamin D supplementation, and season were noted.

Among 1311 children, higher cow's milk consumption was associated with higher 25-hydroxyvitamin D (P0.0001) levels and lower serum ferritin (P75 nmol/L with minimal negative effect on serum ferritin for most children. However, during the winter, children with darker skin types were vitamin D deficient at 2 cups of milk per day.

CITATION(S):

Maguire JL et al. The relationship between cow's milk and stores of vitamin D and iron in early childhood. Pediatrics 2013 Jan; 131:e144.