"nBackground: The aim of study was to assess serum homocysteine and its relation with serum folate, vit B12 and lipid pro­files in gestational diabetes mellitus and comparison with normal pregnant women as well as effect of different doses of fo­lic acid on Homocysteine (Hcy) and pregnancy outcome."nMethods:  In a biphasic study first prospective controlled study 80 pregnant women were chosen at 24-28 weeks of gesta­tion. In case group pregnant women with gestational diabetes mellitus and control group who had normal Oral Glucose Toler­ance test (GTT) results. Levels of fasting glucose, homocysteine, vit B12, and folic acid, uric acid, total cholesterol, triglyc­eride, LDL, HDL, were measured. In phase II study a randomized clinical trial was done with diabetic women 15 with 1mg folic acid and 15 with 5 mg folic acid for six weeks and then above variables and pregnancy outcome was evalu­ated."nResults: The mean levels of homocysteine in Gestational Diabetes Mellitus (GDM) group were significantly higher but fo­lic acid and vit B12 were significantly lower. Hcy levels were decreased in both groups after six weeks folic acid but de­crease in Hcy for group 5mg was significantly more than 1mg group. "nConclusion: Homocysteine levels were higher in GDM than normal pregnancy. High dose folic acid can reduce Hcy levels more than low dose and it may be a safe, simple, inexpensive intervention that prevents major pregnancy complications. "n&nbsp