OBJECTIVE: We undertook a systematic review to assess normative levels of vitamin D in
early pregnancy and association with subsequent pregnancy outcomes. STUDY DESIGN:
Medline and Embase databases and reference lists were searched. Inclusion criteria were
pregnant populations, blood sample taken during the first trimester, and serum
hydroxyvitamin D levels assessed. RESULTS: Eighteen studies reported vitamin D levels in
first trimester (n= 11-3730), and 5 examined pregnancy outcomes. Mean vitamin D�…