 Each participant of each group will be given the medication of preterm birth hospital protocol, which includes nifedipine 4x10 mg as tocolytic agent, dexamethasone 2x6 mg intravenous for 2 days which aims to support lung maturation, and antibiotic. Then, the blood sample is obtained for zinc, vitamin A and 25OHD levels examination. Subjects will be divided into 2 groups which are group whose given the oral zinc 50 mgday, oral beta-carotene 25,000 IU and oral vitamin D3 50,000 IUweek supplementation, and group who is not given the intervention. Each participant will be observed until delivery. After delivery, level of zinc, vitamin A, and 25OHD in serum and placenta will be measured, as well as level of MyD88, TRIF, NFκB, and IL-1β in placenta. 