Vitamin D deficiency is highly prevalent worldwide and certain groups as elderly persons women and institutionalized persons are particularly prone to severe deficiency. Objective: To identify the prevalence of hypovitaminosis D and its relation to cardiovascular risk among elderly diabetic female patients. Method: A cross sectional study conducted from the first of October 2014 to the end of March, 2016, where 163 elderly diabetic females who attended Ain shams university hospital at that time were included. They underwent careful history taking, body mass index calculation, blood pressure measurement and Serum 25(OH) D measurement, assessment of insulin secretion including fasting serum C-peptide and CPI measurement in addition to assessment of glycemic control by fasting blood sugar estimation. The level of 25 hydroxy vitamin D (25OHD) was measured. Results: The prevalence of vitamin D deficiency (25OHD level <20 ng/mL ) and insufficiency (25OHD concentration of 20–29 ng/mL) among elderly Egyptian diabetic female patients are 71.2% and 28.2% resp. There is statistically significant association between vitamin D deficiency and low fasting C peptide level and c peptide index. The 3 independent predictor of the presence of vitamin D deficiency were types of diabetic medications, low C-peptide and CPI values and upon logistic regression analysis for these 3 variables, lower CP level was an independent predictor of the presence of vitamin D deficiency. Results showed a weak negative correlation between serum 25(OH)D, systolic BP, BMI and HOMA IR in studied subjects. Conclusion: Prevalence of vitamin D deficiency among elderly Egyptian diabetic female patients is 71.2%. There is statistically significant association between vitamin D deficiency and low fasting C peptide level and c peptide index.