Low Vitamin D Increases Mortality Risk

A comprehensive population-based study finds that low levels of 25-hydroxyvitamin D is linked with all-cause death.
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Daniel Dudenkov, MD, of the Mayo Clinic in Rochester, Minnesota, reported on a 25-hydroxyvitamin D level study, at the annual meeting of the American Society for Bone and Mineral Research. The comprehensive population-based study involved people ages 18 and older in Olmsted County, Minn., who were enrolled in a Rochester Epidemiology Project from the years 2005 to 2011. Previous studies had not been population based, so he conducted a retrospective study to clarify those observations. Participants in the study were followed after 30 days from their first measurement of vitamin D, until one of three things happened: leaving the study, December 31, 2014, or death. There were 11,022 individuals with a mean age of 54, over three-quarters were women, and close to 90% were white. The analysis was adjusted for sex, age, race, the comorbidity index, and which month the level was obtained. They had a mean vitamin D level of 30 ng/mL with 643 participants having levels below 12, 1,605 having levels between 12 and 19, 8,210 having levels between 20 and 50, and 564 with levels higher than 50 ng/mL.

During a 4.8-year follow-up, there were 723 deaths. Increased all-cause mortality was associated with low vitamin D levels. Individuals with serum 25-hydroxyvitamin D levels below 20 ng/mL had an adjusted hazard ratio for death of 2.37 and 12 to 20 ng/mL 1.28. Below 20 ng/mL and above 50 ng/mL were associated with chronic adverse events which included increased cancer, cardiovascular, and respiratory diseases mortality. There was a significant interaction by race. Whites with vitamin D levels below 12 ng/mL, the hazard rate (HR) was 2.83 while for non-whites, the HR was 1.76. Whites with levels between 12 and 19 ng/mL had an HR of 1.42 while non-whites had an HR of 1.52. White men with levels below 12 ng/mL had an HR of 4.46, and non-white men had a 2.77. White women had corresponding HRs of 2.83 and 1.76. A difference was also seen for whites and non-whites according to age. Participants age 70 and older with vitamin D levels below 12 ng/mL had an HR for whites of 1.30 compared with 0.81 for non-whites.

Vitamin D is very important because it has a role in bone metabolism, as well as falls and fractures, and it has effects on diabetescancer, the cardiovascular system, calcification of blood vessels, and some effects in the brain.

NOTE:  This study was presented at a conference and was published as an abstract. The data and conclusions should be recognized as preliminary until they are published in a peer-reviewed journal.

American Society for Bone and Mineral Research
Source Reference: Dudenkov D, et al "Serum 25-hydroxyvitamin D values and risk of all-cause mortality: a population-based, retrospective cohort study" ASBMR 2016; Abstract FR0001.