2.2.2 Infants from birth to 12 months: Infants have limited stores of vitamin D at birth because the amount transferred from the mother has a very short half life of 10-21 days (1). For infants exclusively breastfed, vitamin D supplementation is recommended by Health Canada (5) because vitamin D concentrations are low in the breast milk of Canadian mothers (4-40 IU/L). Fortified formula would provide ~ 400 IU vitamin D/L daily, but likely not achieved until close to 6 months of age (i.e., with intake 1L/d). After 6 months of age, the foods available to infants have limited vitamin D content.