The Vitamin D deficiency was significantly related to: pregnancies at 26 - 35 years old vs teen (PR * = 0.5), others vs Kinh ethnic (PR * = 2.01), low economic status (PR * = 2.60), nulliparous vs multifarious (PR * = 0.45), pregnant fatigue (PR * = 1.68), gain weight at first trimester (PR * = 0.70), working outdoors (PR * = 0.58).