A new study is the first to show that combining weight loss with an inexpensive vitamin supplement can reduce chronic inflammation more than weight loss alone. Chronic inflammation has been linked to a wide range of disorders, from cardiovascular disease to type 2 diabetes, Alzheimer’s disease, depression, and even cancer.
The findings from a randomized clinical trial at Fred Hutchinson Cancer Research Center were published in Cancer Prevention Research. The study included 218 healthy, but overweight postmenopausal women with below-normal levels of vitamin D. Vitamin D levels can be measured with a simple blood test.
All participants followed a 12-month weight-loss program that included 45 minutes of moderate-to-vigorous exercise. Half of the women were randomly assigned to take 2,000 i.u. of vitamin D daily (more than triple the current recommended dietary allowance) while the other half took a placebo. The women’s levels of inflammatory biomarkers were measured at the start and end of the study. The study found that combining Vitamin D and weight loss reduced inflammation by 37%.
“We know from our previous studies that by losing weight, people can reduce their overall levels of inflammation, and there is some evidence suggesting that taking vitamin D supplements can have a similar effect if one has insufficient levels of the nutrient,” said lead study author Catherine Duggan, Ph.D., a principal staff scientist in the Public Health Sciences Division at Fred Hutchison Cancer Research Center.
However, it was not known if combining the two–weight loss and vitamin D supplements–would increase the effect. ““It’s the first study to test whether adding vitamin D augments the considerable effect of weight loss on inflammatory biomarkers,” added Duggan.
At the end of the trial, all participants had lower levels of inflammation, “which highlights the importance of weight loss in reducing inflammation,” Duggan said.
However, the most dramatic decline occurred in women who had taken vitamin D and lost 5 to 10 percent of their starting weight. In these participants, levels of the inflammatory biomarker interleukin-6 (IL-6) fell by 37 percent, versus a 17.2 percent drop in the placebo group.
“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,” reported Duggan. “That suggests vitamin D can augment the effect of weight loss on inflammation.”
Vitamin D Aids Weight Loss–and May Reduce Heart Attack and Stoke Risk
Vitamin D has unique characteristics. Unlike other vitamins, which we can only get from foods or supplements, vitamin D is produced naturally when our skin is exposed to sunlight. Another unique characteristic is that our bodies convert vitamin D into a hormone with a variety of functions in the body beyond its well-known bone health benefits.
A 2014 clinical trial by the same researchers compared the effects of vitamin D supplementation versus placebo in overweight women who initially tested low for vitamin D. After following a 12-month diet-and-exercise program, those who achieved healthy levels of vitamin D through supplementation lost more weight (an average of 19 pounds), compared to women who maintained low levels (an average weight loss of 12 pounds).
In addition, the women who achieved healthy levels of vitamin D had improved levels of insulin and the inflammatory biomarker high-sensitivity C-reactive protein (hsCRP). “This suggests women trying to lose weight might want to have their D levels checked by their provider and replenish their vitamin D levels either through supplements or sun and then have their D levels rechecked after a few months to make sure they’ve risen to a healthy level,” said Anne McTiernan, MD, PhD., principal investigator of the study.
Up to 75 Percent of Americans Are Low in Vitamin D
As we recently reported, up to 75 percent of Americans have low levels of vitamin D–a condition, studies suggest, that may be an independent risk factor for heart attack and stroke. A growing body of research also suggests increasing vitamin D levels may help prevent heart disease, the leading killer of men and women.
A 2014 meta-analysis found that vitamin D supplementation can significantly improve levels of hsCRP. Research shows that apparently healthy people with high hsCRP levels are up to four times more likely to have coronary artery disease and are also at increased risk for heart attack, stroke, and death from cardiovascular causes.