Trial to Assess Vitamin D Requirements in Lactating Women

Inclusion Criteria: * Pregnant women intending to breast feed their infant for at least 12-weeks * Pregnant women \>20 weeks gestation * Pregnant women \>18 years of age * Pregnant women in good general health Exclusion Criteria: * Consumption of a vitamin D-containing supplement(\>10µg/day) in the 3 months prior to commencing the trial * Consumption of a vitamin D or calcium containing supplement during the 12- week trial * Mothers taking a vacation to a sunny climate or using a solarium during the 12-week trial * Mothers with pre-existing type 1 or type 2 diabetes * Mothers with pre-existing hypertension * Mothers with diagnosed hypercalcemia * Mothers with diagnosed intestinal malabsorption conditions * Mothers with multiple fetuses (e.g. twins) * Consumption of medications known to interfere with vitamin D metabolism.