The risk of all-cause mortality is inversely related to serum 25(OH)D levels.
OBJECTIVE
Vitamin D plays a key role in maintaining bone health, but evidence for its nonskeletal effects is inconsistent. This study aims to examine the association between serum 25-hydroxyvitamin D [25(OH)D] levels and all-cause mortality in a large general population cohort.


METHODS
Using the computerized database of the largest health care provider in Israel, we identified a cohort of subjects 20 years old or older with serum 25(OH)D levels measured between January 2008 and December 2009. Vital status was ascertained through August 2011.


RESULTS
Median follow-up was 28.5 months (interquartile range 23.8-33.5 months); 7,247 of 182,152 participants (4.0%) died. Subjects who died had significantly lower serum 25(OH)D levels (mean 44.8 ± 24.2 nmol/liter) than those alive at the end of follow-up (51.0 ± 23.2 nmol/liter), P < 0.001. After adjustment for age, gender, ethnicity, and seasonality, the hazard ratio (HR) for all-cause mortality was 2.02 [95% confidence interval (CI) 1.89-2.15] for the lowest serum 25(OH)D quartile (<33.8 nmol/liter) compared with the highest. After further adjustment for comorbidity, use of vitamin D supplements and statins, smoking, socioeconomic status, and body mass index, the HR was 1.81 (95% CI 1.69-1.95). This remained, even after adjustment for serum low-density lipoprotein, high-density lipoprotein, calcium level (corrected for serum albumin levels), and glomerular filtration rate, 1.85 (95% CI 1.70-2.01). The fully adjusted HR associated with being in the second 25(OH)D quartile (33.8-49.4 nmol/liter) was 1.25 (95% CI 1.16-1.34).


CONCLUSIONS
All-cause mortality is independently and inversely associated with serum 25(OH)D levels at levels less than 50 nmol/liter.
Department of Community Medicine and Epidemiology, Carmel Medical Center, Clalit Health Services, and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 34362, Israel. saliba_wa@clalit.org.il
Walid
W
Saliba
Ofra
O
Barnett
Hedy S
HS
Rennert
Gad
G
Rennert
D000328:Adult; D000368:Aged; D002423:Cause of Death; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009026:Mortality; D016016:Proportional Hazards Models; D012306:Risk; D014807:Vitamin D / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood
D014807:Vitamin D; C104450:25-hydroxyvitamin D