New study demonstrates synergistic effects of vitamin D and estradiol deficiency on metabolic syndrome

A combination of vitamin D and estrogen could prevent metabolic syndrome and the corresponding increased risk of heart disease, stroke, and diabetes in postmenopausal women, according to a new study published in the journal Menopause.

Researchers from China conducted a cross-sectional study, including 616 postmenopausal women age 49 to 86 years old who were not taking estrogen and vitamin D or calcium supplements at the beginning of the trial.

Higher vitamin D was associated with a favorable lipid profile, blood pressure, and glucose level. Estradiol was negatively associated with cholesterol, triglycerides, and blood pressure. These results suggest a synergistic role of vitamin D and estradiol deficiency in developing metabolic syndrome in postmenopausal women, researchers said.

Metabolic syndrome has emerged as a major public health concern, affecting 30 percent to 60 percent of postmenopausal women worldwide. The progression of abdominal obesity and heart disease that lead to metabolic syndrome increases significantly as women age and appears to be directly associated with estrogen loss in postmenopausal women. This has led some researchers to recommend estradiol treatment for women who are fewer than six years postmenopausal as a means of preventing heart disease.

Similarly, vitamin D has been associated with several markers of metabolic syndrome, including obesity, hyperglycemia, insulin resistance, and type 2 diabetes mellitus. Supplementation with vitamin D has been shown to reduce the risk of metabolic syndrome over a 20-year follow-up.

In this study, low estradiol increased the risk of metabolic syndrome in postmenopausal women who had vitamin D deficiency, according to JoAnn Pinkerton, MD, executive director of the North American Menopause Society. The Endocrine Society recommends vitamin D levels of 30 ng/mL for postmenopausal women. Whether adequate levels of vitamin D improve non-skeletal cardiovascular or cognitive benefits remains the subject of debate, and answers await randomized clinical trial data.