Reprtinted with the kind permission of Life Extension
December 21 2016. An article appearing on November 15, 2016 in Frontiers in Physiology
reports an essential role for vitamin D deficiency in the development of metabolic syndrome, a group of characteristics associated with an increased risk of diabetes and cardiovascular disease.
Yuan-Ping Han and colleagues at Sichuan University, China divided 40 mice to receive a control diet supplemented with a sufficient amount of vitamin D3, a vitamin D deficient control diet, a high fat diet supplemented with vitamin D3, or a high fat diet that was deficient in vitamin D for 18 weeks. The team found that a high fat diet is necessary but not sufficient by itself to induce insulin resistance and fatty liver, and that “a second hit,” in the form of vitamin D deficiency, is required.
It was demonstrated that a high fat diet alters gut bacteria, which contributes to elevated glucose and fatty liver. This imbalance is aggravated by a lack of vitamin D, which results in decreased production of antimicrobial molecules called defensins that are needed to maintain healthy intestinal flora. In animals that received high fat, vitamin D deficient diets, oral administration of synthetic defensin improved intestinal bacteria balance.
"We are planning a clinical study to confirm the link of vitamin D deficiency with gut bacteria disruption, and its association with metabolic syndrome," Dr Han announced.
"Based on this study, we believe that keeping vitamin D levels high, either through sun exposure, diet or supplementation, is beneficial for prevention and treatment of metabolic syndrome," stated coauthor Stephen Pandol, of Cedars-Sinai Medical Center in Los Angeles. "A sufficient dietary vitamin D supplement can partially but significantly antagonize metabolic syndrome caused by high fat diet in mice. These are amounts equivalent to the dietary recommendations for humans."