Despite the relative abundance of sunny weather, surprisingly, there is increasing evidence that vitamin D deficiency is extremely prevalent in females of reproductive age in Middle East countries. There is also increasing interest in the non-classical roles of vitamin in health and disease including its relation to incidence of gestational diabetes, its impact on glycaemic control in diabetes mellitus, and its association with some complications of pregnancy like preeclampsia. The objective of this study was to estimate the prevalence of Vitamin D deficiency in pregnant diabetic patients in west Libya and analyse potential links to socioeconomic and cultural factors. This is a cross sectional observational study. Random plasma was collected form expected mothers attending the Antenatal Diabetes Clinic at Tripoli's Main Maternity Hospital. Demographics and socioeconomic and cultural factors were recorded at the same time. Samples were analysed for vitamin D level and biochemical screening panel. Vitamin D level was obtained from 160 patients (mean age 35 years). Over all 95 % of the study population had vitamin D levels below normal (defined as vitamin D level of < 20 ng/mL). Results were subcategorised into severe deficiency (<10 ng/ml, 51.9%-83 patients), deficiency (< 20 ng/mL, 43.1%, 69 patients), insufficiency (20 -30 ng/ml, 3.8%, 6 patients) and sufficient (> 30 ng/ml, only 1.3%, 2 patients). All patients were taking daily vitamin D Supplements at a dose of 400 IU as per hospital policy. Vitamin D deficiency is extremely prevalent in pregnant diabetic patients in Libya. There is no clear association with socioeconomic risk factors like employment, type of accommodation or geographic distribution. However, most of the study population had life style characterized by minimal exposure to direct sun