Widespread Vitamin D Deficiency in Urban Massachusetts Newborns and Their Mothers

Abstract

OBJECTIVE: To determine vitamin D status and associated factors in a cohort of newly delivered infants and their mothers in Boston, Massachusetts. PATIENTS AND METHODS: Enrollment in this cross-sectional study took place from 2005 to 2007 in an urban Boston teaching hospital with 2500 births per year. A questionnaire and medical-record data were used to identify variables that are potentially associated with vitamin D deficiency (25-hydroxyvitamin D [25(OH)D] < 20 ng/mL). Infant and maternal blood was obtained by venipuncture within 72 hours of birth. The main outcome measure was infant and maternal 25(OH)D status, assessed by competitive protein binding. RESULTS: We enrolled 459 healthy mother/infant pairs. After subsequent exclusions, analyses were performed on 376 newborns and 433 women. The median infant 25(OH)D level was 17.2 ng/mL (95% confidence interval [CI]: 16.0–18.8; range: 30% of the women who took prenatal vitamins were still vitamin D deficient at the time of birth. CONCLUSIONS: A high proportion of infants and their mothers in New England were vitamin D deficient. Prenatal vitamins may not contain enough vitamin D to ensure replete status at the time of birth.