Vitamin D deficiency mortality
Pro Research Analysisby 
Searched over 200M research papers
Vitamin D Deficiency and All-Cause Mortality Risk
Multiple large studies consistently show that vitamin D deficiency, defined by low serum 25-hydroxyvitamin D (25(OH)D) levels, is linked to a higher risk of all-cause mortality in the general population. Individuals with deficient vitamin D levels have a significantly increased risk of death compared to those with sufficient levels, with the risk rising steeply as vitamin D levels fall below 50 nmol/L and especially below 30 nmol/L 123567. This association is non-linear, with the greatest reduction in mortality risk observed as vitamin D levels increase from very low to moderate concentrations, but little additional benefit at very high levels 2567.
Vitamin D Deficiency and Cause-Specific Mortality
Research indicates that vitamin D deficiency is particularly associated with increased mortality from respiratory diseases and infections, including pneumonia, and to a lesser extent with cardiovascular disease mortality 23456910. However, the evidence for a direct link between vitamin D deficiency and cancer or cerebrovascular mortality is weaker or inconsistent 356.
Vitamin D Deficiency in Critically Ill and Hospitalized Patients
Among critically ill patients, vitamin D deficiency is highly prevalent and is strongly associated with increased hospital and 30-day mortality, as well as higher rates of infection and sepsis 4910. These findings are consistent across multiple cohort studies and meta-analyses, suggesting that vitamin D status is an important prognostic factor in intensive care settings 4910. Ongoing randomized controlled trials are investigating whether high-dose vitamin D supplementation can improve survival in this high-risk group .
Population Prevalence and Demographic Factors
Vitamin D deficiency is common, affecting a significant proportion of middle-aged and older adults in both Europe and North America, with prevalence rates ranging from 4.6% to over 40% depending on the population and threshold used 139. Deficiency is more common in younger, male, non-white, less educated, and lower-income individuals, as well as those with higher body mass index .
Causality and Supplementation
Genetic studies and meta-analyses support a likely causal relationship between vitamin D deficiency and increased mortality risk, especially at very low vitamin D levels 256. Some evidence suggests that vitamin D supplementation may reduce mortality in middle-aged and elderly populations, but more research is needed to determine the effectiveness of supplementation in improving survival, particularly in specific patient groups and the critically ill 18.
Conclusion
There is strong and consistent evidence that vitamin D deficiency is associated with increased risk of all-cause and infection-related mortality in both the general and critically ill populations. The greatest risk is seen at very low vitamin D levels, and raising these levels to at least 50 nmol/L may reduce premature death. Further research is needed to clarify the benefits of supplementation and to identify optimal strategies for improving vitamin D status in at-risk groups.
Sources and full results
Most relevant research papers on this topic