IRCT201410035623N27 IRCT 2014-10-04 Arak University of Medical Sciences Effect of supplementation in treatment of pregnancy complications Effects of vitamin D supplementation on metabolic profiles in pregnant women who are at risk of pre-eclampsia 2014-06-22 anticipated 60 Complete https://irct.ir/trial/6057 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Randomization description: At study baseline and after stratification for pre-intervention BMI and age, subjects will be randomly divided into two groups to take either vitamin D supplements (n=30) or placebo (n=30). Randomization will be done by the use of computer-generated random numbers, Blinding description: Randomization and allocation will be concealed from the researchers and participants until the final analyses are completed. Another person at gynecology clinic affiliated to Arak University of Medical Sciences, who is not involved in the trial and not aware of random sequences, will be assigned the participants to the numbered bottles of capsules. 3 Pregnancy. Intervention 1: Intervention group: Vitamin D pearl, 50000 IU, each two weeks for 12 weeks. Intervention 2: Control group: Placebo pearl, each two weeks for 12 weeks. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is Undecided - It is not yet known if there will be a plan to make this available