In the univariate analysis the hazard ratio (HR) at 2-year follow-up for all-cause mortality in the highest as compared to the lowest quartile of 25(OH)D in the total population was 0.61 (95% confidence interval (CI), 0.37–1.00), . At 7-year follow-up, the corresponding HR for all-cause mortality was 0.66 (95% CI, 0.49–0.90), , and for females alone 0.51 (95% CI, 0.32–0.83), . Quartile survival did not differ in the multivariable analysis, whereas 25(OH)D < 40 nM (<16 ng/mL) was found to be independently related to mortality.Seasonal differences in 25(OH)D, but not for the omega-3 index, were noted, and the two biomarkers were positively correlated, especially during winter-spring; Pearson’s correlation coefficient was 0.358, . Conclusion. Vitamin D levels are related to survival, especially in females, and correlate with the omega-3 index.