Aging increases the risk of both vitamin D deficiency and metabolic syndrome. Vitamin D deficiency and metabolic syndrome may be related, although there are mixed findings. Furthermore, literature suggests other factors such as physical fitness activity and smoking behavior are associated with Vitamin D deficiency and the development of metabolic syndrome. A number of studies have documented associations between Vitamin D levels and physical fitness activities, while other studies found correlations between Vitamin D levels, metabolic syndrome, and smoking behavior. However, no previous study has examined the links between physical fitness activity, smoking behavior, Vitamin D levels, and the risks for metabolic syndrome. The purpose of this study was to examine if smoking behavior and physical fitness activity moderated the relationship between Vitamin D deficiency and metabolic syndrome among older individuals. The research problem was addressed through the use of retrospective data collected from the National Health and Nutrition Examination Survey (NHANES) 2005-2006. This study utilized a quantitative, retrospective, cross-sectional design employing regression and correlational analysis to determine that Vitamin D deficiency (p = 0.02) predicts metabolic syndrome (n = 1570). However, neither physical activity (p = 0.99) nor smoking behavior (p = 0.23) moderated the relationship between Vitamin D deficiency and metabolic syndrome (n = 1570). The results of the study could give practitioners a better understanding and insights into the different risk factors to metabolic syndrome among older individuals, which can eventually enable primary and secondary prevention interventions.