Low vitamin D again linked to higher mortality

Low blood levels of vitamin D have again been linked to lower survival in the elderly, a new study reports.

The new study used data from 614 people participating in a prospective population-based study with men and women with an average age of 69.8 (1). Blood levels of 25(OH)D were measured at the start of the study. After an average of six years of follow-up, people with the lowest average vitamin D levels (30.6 nanomoles per liter) were found to be at a 124 and 378 percent increased risk of all-cause mortality and cardiovascular mortality, respectively.

The researchers said that the results provide a rationale for future studies to test whether vitamin D supplementation reduces mortality and/or cardiovascular diseases in persons with vitamin D deficiency. Apart from the maintenance of muscular and skeletal health, vitamin D may also protect against cancer, infections, autoimmune and vascular diseases, suggesting that vitamin D deficiency might contribute to a reduced life expectancy.

The research follows similar findings in 714 community-dwelling women, aged between 70 and 79 years, participating in the Women's Health and Aging Studies I and II (2). The scientists noted that several biologic mechanisms could explain a causal relationship between vitamin D deficiency and mortality, with the vitamin’s active form (1,25-dihydroxyvitamin D) linked to a range of effects including control of inflammatory compounds, regulating immune health and blood pressure, or reducing arterial hardening.

1. Pilz S. et al. Vitamin D and mortality in older men and women. Clinical Endocrinology. 2009; 71(5):666–672.
2. Semba R.D. et al. Low serum 25-hydroxyvitamin D concentrations are associated with greater all-cause mortality in older community-dwelling women. Nutrition Research. 2009; 29:525–530.