November 11, 2019
By Reuters Staff
NEW YORK (Reuters Health) - Vitamin D or omega-3 fatty acid supplementation does not preserve kidney function in patients with type 2 diabetes, new research shows.
There was no significant difference in changes in glomerular filtration rate over five years in patients on either supplement, or both, compared to placebo, Dr. Ian H. de Boer of the University of Washington, Seattle, and colleagues found.
"These results suggest that neither vitamin D nor omega-3 fatty acids have appreciable kidney benefits among the broad population of patients with diagnosed type 2 diabetes," they conclude in their report, published online November 8 in JAMA to coincide with a presentation at Kidney Week in Washington, DC.
The findings are from an ancillary study to the Vitamin D and Omega-3 Trial (VITAL), in which patients with type 2 diabetes across the U.S. were randomly assigned to 2,000 IU of vitamin D3 and 1 gram of eicosapentaenoic acid and docosahexaenoic acid per day, vitamin D and placebo, omega 3s and placebo, or two placebos for five years.
Mean eGFR at baseline was 85.8 mL/min/1.73m2, and mean change at five years was -12.4 mL/min/1.73m2 in the 932 patients with data available at both time points. There were no significant differences in eGFR change among the four treatment groups. There were also no differences in the percentage of patients with a 40% or greater eGFR decline, kidney failure, or death among the groups.
In an accompanying editorial, Dr. Anika Lucas and Dr. Myles Wolf of Duke University School of Medicine in Durham, North Carolina, note that randomized clinical trials have so far not found any benefits of vitamin D supplementation.
"It now seems safe to conclude that many prior epidemiological associations between vitamin D deficiency and adverse health outcomes were driven by unmeasured residual confounding or reverse causality," they add.
"With each new and carefully conducted negative trial of vitamin D supplementation, the Institute of Medicine's 2010-2011 report that emphasized the bone benefits of attaining sufficient vitamin D stores over other theoretical benefits based on observational data looks ever more prescient," they conclude.
SOURCE: http://bit.ly/2qHqAoD and http://bit.ly/34OdULt
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