Vitamin D status and cause-specific mortality: a general population study

PLoS One. 2012;7(12):e52423. doi: 10.1371/journal.pone.0052423. Epub 2012 Dec 20.

Abstract

Background: Vitamin D deficiency is associated with an increased risk of all-cause mortality in observational studies. The specific causes of death underlying this association lack clarity. We investigated the association between vitamin D status and cause-specific mortality.

Methods: We included a total of 9,146 individuals from the two population-based studies, Monica10 and Inter99, conducted in 1993-94 and 1999-2001, respectively. Vitamin D status was assessed as serum 25-hydroxyvitamin D. Information on causes of death was obtained from The Danish Register of Causes of Death until 31 December 2009. There were a total of 832 deaths (median follow-up 10.3 years).

Results: Multivariable Cox regression analyses with age as underlying time axis and vitamin D quartiles showed significant associations between vitamin D status and death caused by diseases of the respiratory system, the digestive system, and endocrine, nutritional and metabolic diseases with hazard ratios (HRs) 0.26 (p(trend) = 0.0042), 0.28 (p(trend) = 0.0040), and 0.21 (p(trend) = 0.035), respectively, for the fourth vitamin D quartile compared to the first. We found non-significantly lower HRs for death caused by mental and behavioural diseases and diseases of the nervous system, but no association between vitamin D status and death caused by neoplasms or diseases of the circulatory system.

Conclusion: The associations of vitamin D status and cause-specific mortality suggest that we also look elsewhere (than to cardiovascular disease and cancer) to explain the inverse association between vitamin D status and mortality.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cause of Death*
  • Confidence Intervals
  • Denmark / epidemiology
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Mortality*
  • Proportional Hazards Models
  • Risk Factors
  • Vitamin D / analogs & derivatives
  • Vitamin D / blood*

Substances

  • Vitamin D
  • 25-hydroxyvitamin D

Grant support

The present study was supported by The Health Insurance Foundation (grant number 2010 B 131). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.