Vitamin D requirements and vitamin D intoxication in infancy.

Without vitamin D supplementation, the majority of infants seems to be at risk of vitamin D-deficiency rickets. On the other hand, routine vitamin D supplementation of breast-fed infants is not recommended by all authors. In this paper we give an overview of vitamin D metabolism and vitamin D regulation in newborns, which may differ in a certain way from the regulation in adults. Based on this, minimal and optimal requirements for vitamin D in newborns and infants is determined. Furthermore, the paper aims at defining dosages and conditions that are at risk of vitamin D intoxication.