ABSTRACT
Vitamin D requirements during pregnancy and lactation were unvarying for decades: Women were thought to obtain all that they needed from their prenatal vitamin containing 400 IU vitamin D. Data have accumulated that demonstrate otherwise. In this chapter, we review the differences in vitamin D metabolism during pregnancy and lactation and the implications of these differences on vitamin D sufficiency important for both the mother and her developing fetus during pregnancy and for both the mother and her breastfeeding infant during lactation. A summary of relevant clinical trials that have been conducted to answer the question of what amount of vitamin D is necessary to optimize its metabolism during pregnancy and lactation will also be reviewed. More questions than answers remain, however, regarding the impact of vitamin D on immune function and inflammation during pregnancy and lactation and the long-term implications of vitamin D on the health of the child.
