100: Non-Dairy Milk Consumption is Associated with Lower Serum 25-Hydroxyvitamin D in Early Childhood

Abstract

Vitamin D fortification of cow's milk is the main dietary source of vitamin D in early childhood. The consumption of non-dairy milk, such as plant-based milk beverages and goat's milk is increasing. Vitamin D fortification of non-dairy milk is voluntary in North America. We hypothesize that the consumption of non-dairy milk may be associated with lower 25-hydroxyvitamin D in early childhood. For our primary objective, we aimed to determine if there is an association between daily volume of non-dairy milk consumption and serum 25-hydroxyvitamin D in healthy young Canadian children. For our secondary objective we aimed to explore whether cow's milk consumption modifies this relationship. Children attending one of seven pediatric or family medicine primary care practices were recruited during routine primary healthcare. For our primary analysis, a multiple linear regression model was developed to test the association between daily volume of non-dairy milk consumption and 25-hydroxyvitamin D, adjusted for age, gender, z-BMI, season, vitamin D supplementation, skin pigmentation, and daily outdoor play time. To explore whether cow's milk modifies this relationship, the interaction between non-dairy milk and cow's milk consumption was included in this model. A total of 2831 children were included in the analysis. Mean age was 2.9 years, 53% were male, 53% were taking a vitamin D containing supplement, 87% of children were consuming cow's milk and 13% of children consumed non-dairy milk daily. In the univariate analysis, each cup of non-dairy milk consumed per day was associated with a 2.3 nmol/L (P=0.005, 95% CI 1.0, 4.9) lower mean 25-hydroxyvitamin D concentration. Multiple linear regression, adjusted for clinically relevant covariates, revealed that each additional 250 ml cup of non-dairy milk was associated with a 3.8 nmol/L (95% CI 1.0 to 8.6; P=0.01) lower 25-hydroxyitmian D among children who drink cow's milk, and a non-significant increase in 25-hydroxyvitmain D of 0.3 nmol/L (95% CI −3.0 to 3.1; P=0.6) among children who do not drink cow's milk. Non-dairy milk consumption is associated with a lower 25-hydroxyvitamin D level in early childhood. This relationship appears to be modified by cow's milk consumption, suggesting that consumption of lower vitamin D containing non-dairy milk may be replacing consumption of higher vitamin D containing cow's milk.