In May 2019 researchers from Turkey published their study to assess the effect of vitamin D supplementation in overweight and obese pre-menopausal women. Vitamin D deficiency is a common problem and is related to an increased risk of obesity, metabolic syndrome, atherosclerosis and cardiovascular disease. It is also known that vitamin D has a beneficial effect on dyslipidemia and insulin secretion. A total of 72 overweight and 50 obese pre-menopausal women, average age 43 years, with vitamin D deficiency were included in the study. At the start of the study, vitamin D levels ranged from 2.9-15.8 ng/ml in the overweight group and 3.0-22.0 ng/ml in the obese group (some sources suggest that levels above 30ng/ml are ‘sufficient’, whilst 28-32 ng/ml is considered ‘optimal’). In addition to vitamin D levels, intact parathyroid hormone, calcium, phosphorus, insulin resistance levels and lipid profiles were assessed. The assessments were repeated at six months. Results showed that following vitamin D supplementation, vitamin D levels increased to 34.7 ng/ml in both groups of individuals. In addition, there was a significant improvement in insulin resistance, as well as LDL(bad)-cholesterol and intact parathyroid hormone levels. A analysis revealed that for every 1 ng/ml increase in vitamin D level there was a 0.30-fold reduction in the level of insulin resistance.
Imga NN et al. Effects of vitamin D supplementation on insulin resistance and dyslipidemia in overweight and obese premenopausal women. Arch Med Sci. 2019 May;15(3):598-606