Low blood vitamin D concentration may increase mortality risk

Low levels of vitamin D are associated with increased mortality in older African American and Caucasian adults, says a new US study.

In this observational study, the blood vitamin D concentrations, medical conditions and proportion of deaths of 2,638 Caucasians and African Americans aged 70 to 79 were measured (1). In addition to many health factors, the time of year was also taken into account due to the seasonal effects on vitamin D. The study results showed that vitamin D levels of less than 30 ng/ml were associated with significantly increased all-cause mortality. Observed in one-third of study participants, vitamin D insufficiency (defined as blood levels below 20 ng/ml) was associated with a nearly 50% increase in the mortality rate. The findings also indicated that the potential positive impact of remediating low vitamin D levels is greater in African Americans than Caucasians because vitamin D insufficiency is more common among African Americans.

The researchers commented that low levels of vitamin D may be a substantial public health concern for our nation’s older adults. For the past several years, there has been considerable interest in the role vitamin D plays in improving health and preventing disease. Low levels of vitamin D have been directly associated with various forms of cancer and cardiovascular disease.

1. Kritchevsky S. B. et al. 25-Hydroxyvitamin D, Parathyroid Hormone, and Mortality in Black and White Older Adults: The Health ABC Study. Journal of Clinical Endocrinology and Metabolism. Published online October 2012.