This study is a longitudinal, observational follow-up of MUSC subjects previously enrolled in the NIH funded Tolsurf study. It is being conducted to determine the developmental impact of NICU exposures to chemical plasticizers called phthalates that are found in the NICU environment. Subjects who participated in the Tolsurf study are part of a larger group of NIH funded studies. Participants in each of these NIH funded NICU studies have urine samples from their NICU stay stored in a biobank. These urine samples will be tested for phthalates. If the families agree to let their children participate in the study, results of pulmonary testing and developmental testing will be compared to levels of phthalates in the urine collected during their NICU stay. Previous studies have linked phthalates in-utero to developmental delays, asthma, and altered onset of puberty. The aims of the DINE study are to identify the sources of phthalates in the NICU and measure the impact of phthalates in the NICU.
Breastfeeding is important for the development of the immune system of the infant. Emerging data suggest that vitamin D plays an important role in immunity as well. Exclusively breastfeeding mothers and their infants will be studied in a 3-month (4-study visit) pilot study of vitamin D supplementation versus placebo. Longitudinal effects of vitamin D status on breast milk composition and on the infant's immune system will be examined.
Additionally, exclusively breastfeeding mothers who are currently on vitamin D supplementation will be studied at a single visit, at which mothers will provide a single breastmilk sample and have a single blood sample obtained. These samples will be used to examine effects of vitamin D supplementation on breast milk composition.