Written by Greg Arnold, DC, CSCS. In a study of more than 13,000 patients, researchers found that the group with lowest vitamin D blood levels had a 160% greater risk of kidney failure where dialysis is needed compared to all other patients.
End-stage renal disease is defined as “when the kidneys stop working well enough for you to live without dialysis or a transplant” (1). The condition affects nearly 105,000 Americans and costs our healthcare system more $32 billion each year (2). Risk factors for end-stage renal disease are diabetes, high blood pressure, a family history if kidney disease, heart disease, and being over 60 years old, all of which cause chronic kidney disease and precedes end-stage renal disease (3).
Now a new study (4) has found that vitamin D blood levels may play a role in kidney health. In the study, researchers analyzed vitamin D blood levels from the Third National Health and Nutrition Examination Survey (5) and the incidence of end-stage renal disease in more than 13,000 patients. The researchers found that one in three (34%) of non-Hispanic black individuals had vitamin D levels below 15 nanograms/milliliter, compared to one in twenty (5%) of non-Hispanic white patients. Over the course of 9 years, 65 patients developed end-stage renal disease.
After adjusting for demographic, socioeconomic, and health factors that included diabetes and high blood pressure, the researchers found that patients with vitamin D levels below 15 ng/ml had a 160% increased risk of end-stage renal disease, compared to those with vitamin D levels above 15 ng/ml. When looking at ethnicity, non-Hispanic black individuals had a 183% increased risk of end-stage renal disease, compared to non-Hispanic white patients
For the researchers, low vitamin D blood levels “associate with development of [end-stage kidney disease] even after adjustment for multiple risk factors” and that low vitamin D blood levels “may account for a substantial proportion of the increased risk for [end-stage renal disease] experienced by black individuals.”
The current recommendations by the National Institutes of Health classifies vitamin D deficiency as having blood levels below 10 nanograms/mililiter (27.5 nanomoles/Liter), vitamin D “inadequacy” as having blood levels between 10-15 ng/mL (27.5-37.5 nmol/L), and vitamin D “sufficiency” as having blood levels higher than 15 ng/mL (>37.5 nmol/L) (6).
Source: Melamed, Michal L., et al. “25-hydroxyvitamin D levels, race, and the progression of kidney disease.” Journal of the American Society of Nephrology 20.12 (2009): 2631-2639.
© 2009 by the American Society of Nephrology
Posted January 15, 2010.
References:
- “End Stage Renal Disease” posted on The American Kidney Fund website.
- “Staggering Costs of U.S. Healthcare in the U.S.” posted on The Medical News website.
- “Chronic Kidney Disease” posted on The American Kidney Fund website.
- Melamed ML. 25-Hydroxyvitamin D Levels, Race, and the Progression of Kidney Disease. J Am Soc Nephrol published November 19, 2009 as doi:10.1681/ASN.2009030283.
- “Third National Health and Nutrition Examination Survey (NHANES III) Public-Use Data Files ” posted on The Center for Disease Control and Prevention website.
- “Dietary Supplement Fact Sheet: Vitamin D” posted on The National Institutes of Health website.
