Meta-analysis of all-cause mortality according to serum 25-hydroxyvitamin D

Abstract

We examined the relationship between serum 25-hydroxyvitamin D (25[OH]D) and all-cause mortality. We searched biomedical databases for articles that assessed 2 or more categories of 25(OH)D from January 1, 1966, to January 15, 2013. We identified 32 studies and pooled the data. The hazard ratio for all-cause mortality comparing the lowest (0-9 nanograms per milliliter [ng/mL]) to the highest (> 30 ng/mL) category of 25(OH)D was 1.9 (95% confidence interval = 1.6, 2.2; P < .001). Serum 25(OH)D concentrations less than or equal to 30 ng/mL were associated with higher all-cause mortality than concentrations greater than 30 ng/mL (P < .01). Our findings agree with a National Academy of Sciences report, except the cutoff point for all-cause mortality reduction in this analysis was greater than 30 ng/mL rather than greater than 20 ng/mL.

FIGURE 1—

Results of literature search for studies of serum 25-hydroxyvitamin D in association with all-cause mortality. Note. 25(OH)D = 25-hydroxyvitamin D.

FIGURE 2—

Age-adjusted all-cause mortality hazard ratios comparing lowest with highest categories of serum 25-hydroxyvitamin D, with 95% confidence intervals, in 32 studies of serum 25-hydroxyvitamin D in association with all-cause mortality, 1966–2013. Note. CI = confidence interval

FIGURE 3—

Overall age-adjusted hazard ratios for mortality, in 32 studies of serum 25-hydroxyvitamin D in association with all-cause mortality combined: 1966–2013. Note. 25(OH)D = 25-hydroxyvitamin D.

FIGURE 4—

Dose–response relationships in each study between serum 25-hydroxyvitamin D and age-adjusted hazard ratios for all-cause mortality, in 32 studies of serum 25-hydroxyvitamin D in association with all-cause mortality: 1966–2013 Note. 25(OH)D = 25-hydroxyvitamin D. 1. Thomas et al.; 2. Semba et al. 2010; 3. Zittermann et al.; 4. Jia et al.; 5. Semba et al. 2009; 6. Dobnig et al.; 7. Anderson et al.; 8. Ginde et al.; 9. Virtanen et al.; 10. Von Muhlen et al. (men); 11. Von Muhlen et al. (women); 12. Zhao et al.; 13. Saliba et al.; 14. Schöttker et al.; 15. Johansson et al.; 16. Signorello et al.; 17. Ford et al.; 18. Szulc et al.; 19. Pilz et al. (2009); 20. Visser et al.; 21. Skaaby et al.; 22. Kuroda et al.; 23. Melamed et al.; 24. Pilz et al. (2012); 25. La Croix et al.; 26. Kramer et al.; 27. Kestenbaum et al.; 28. Hutchinson et al.; 29. Michaëlsson et al.; 30. Eaton et al.; 31. Cawthon et al.; 32. Durup et al.; 33. Lin et al.