Results of a randomized, controlled clinical trial conducted by researchers at Fred Hitchinson Cancer Research Center conclude that weight loss in combination with vitamin D supplementation is more effective in reducing chronic inflammation than weight loss alone. Chronic inflammation is known to contribute to the development and progression of several diseases, including some cancers. The results are published online ahead of the July print issue of Cancer Prevention Research. Lead author Catherine Duggan, PhD, noted that previous studies had shown that weight loss can contribute to reduced levels of inflammation, and that some evidence suggests that addressing vitamin D insufficiency via supplements can have a similar effect. This study is the first to test whether adding vitamin D augments the considerable effect of weight loss on inflammatory biomarkers, Duggan said.
The study population was comprised of 218 healthy, overweight older women who had lower-than-recommended levels of vitamin D (less than 32 ng/mL). The women then took part in a 12-month diet and exercise program (including 45 minutes of moderate-to-vigorous exercise five days a week). Half of the study participants were randomly selected to receive 2,000 IU of vitamin D daily for the duration of the year-long trial, and the other half received an identical-appearing placebo, or dummy vitamin. Biomarkers of inflammation were measured at the beginning and end of the study. The researchers then compared changes in these levels between the two groups. “We were quite surprised to see that vitamin D had an effect on an inflammation biomarker only among women who lost at least 5 percent of their baseline weight,” Duggan said. “That suggests vitamin D can augment the effect of weight loss on inflammation.” Read more about the study findings here.