Background. The COVID-19 pandemic goes along with increased mortality from acute respiratory disease, and measures to limit the spread of the infection go along with increased risk of vitamin D deficiency, especially among high risk groups. It has been suggested that vitamin D3 supplementation might help to reduce respiratory disease mortality. Methods. We assessed the prevalence of vitamin D insufficiency and deficiency, defined by 25(OH)D blood levels of 30-50 and <30 nmol/L, respectively, and their association with mortality from respiratory diseases during 15 years of follow-up in a cohort of 9,548 adults aged 50-75 years from Saarland, Germany. Results. Vitamin D insufficiency and deficiency were common (44% and 15%, respectively). Compared to sufficient vitamin D status, respiratory disease mortality was 2.1 (95%-CI 1.3-3.2)- and 3.0 (95%-CI 1.8-5.2)-fold increased, respectively. Although significant increases were seen in both women and men, they were much stronger among women, with 8.5 (95% CI 2.4-30.1) and 2.3 (95% CI 1.1-4.4)-fold increase of respiratory disease mortality in case of vitamin D deficiency among women and men, respectively (p-value for interaction =0.041). Overall, 41% (95% CI 20%-58%) of respiratory disease mortality was statistically attributable to vitamin D insufficiency or deficiency. Conclusion. Vitamin D insufficiency and deficiency are common and account for a large proportion of respiratory disease mortality in older adults, supporting suggestions that vitamin D3 supplementation might make a major contribution to limit the burden of the COVID-19 pandemic, particularly among women.