Vitamin D and insulin resistance

People with a low level of vitamin D in the blood show a poor response to insulin, even when their blood sugar levels are normal. Researchers from the University of California, Los Angeles conducted a study involving 126 healthy, glucose-tolerant subjects and found that low vitamin D has a small but significant impact on blood glucose metabolism and diabetes. The researching team found that the lower the vitamin D concentration, the longer it took for blood glucose levels to decline during oral glucose testing. Overall, subjects with low levels of vitamin D were more likely to exhibit components of so-called metabolic syndrome, such as obesity, high blood pressure and insulin resistance than those with higher concentrations. In particular, 14 of 49 participants classified as having low levels of vitamin D were deemed at risk of the syndrome versus 9 of 79 without such deficiency. However, the study also emphasised that correction of low vitamin D itself is not sufficient in the treatment of these conditions and too much vitamin D could also be harmful.