IRCT201701305623N106 IRCT 2017-02-09 Vice chancellor for research, Ardabil University of Medical Sciences Effect of supplementation in treatment of patients with gestational diabetes Clinical trial of the effect of combined omega-3 fatty acids and vitamin D supplementation compared with the placebo on metabolic profiles and pregnancy outcomes in patients with gestational diabetes 2016-09-08 anticipated 120 Complete https://irct.ir/trial/6136 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Randomization description: 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 the gynecology clinics, who is not involved in the trial and not aware of random sequences, will be assigned the participants to the numbered bottles of capsules.Participants, investigators or the assessors of the outcomes are unaware of the study groups.The appearance of the placebo capsule is indistinguishable in color, shape, size, and packaging, smell and taste from vitamin D and omega-3 fatty acids capsules. 3 Gestational diabetes. Intervention 1: Intervention group: Combined 2000 mg omega-3 fatty acids daily (Zahravi, Tabriz, Iran) and 50000 IU vitamin D every 2 weeks (Zahravi, Tabriz, Iran), for 6 weeks orally. Intervention 2: Intervention group: 2000 mg omega-3 fatty acids daily (Zahravi, Tabriz, Iran), for 6 weeks orally. Intervention 3: Intervention group: 5000 IU vitamin D every 2 weeks (Zahravi, Tabriz, Iran), for 6 weeks orally. Intervention 4: Control group: Omega-3 placebo daily (Zahravi, Tabriz, Iran) and vitamin D placebo every 2 weeks (Zahravi, Tabriz, Iran), for 6 weeks orally. 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.