Hypovitaminosis D has reached epidemic proportions in Qatar. Vitamin D is linked to several cardiometabolic diseases such as metabolic syndrome (MetSyn), diabetes, and atherosclerosis. It is not known if vitamin D status is linked to cardiometabolic risk factors in Qatari women. Therefore, a relationship between serum 25-hydroxyvitmain D [25(OH)D] concentrations and MetSyn was investigated in Qatari women using the Qatar Biobank database. Study sample consisted of 700 women, aged 20-80 years old. A multivariate-adjusted logistic regression was used to determine relation between serum 25(OH)D and MetSyn prevalence. Multivariate linear regression was performed to determine the association between serum 25(OH)D and markers of MetSyn. Prevalences of MetSyn in the first (≈32%), second (≈27%), and third (≈28%) serum 25(OH)D quartiles were significantly higher compared to fourth serum 25(OH)D quartile (≈17.5%) (p < .035). The likelihood of having MetSyn was significantly higher in the first serum 25(OH)D quartile (OR, 1.92; 95% CI, 1.06, 3.49) compared to the fourth serum 25(OH)D quartile (p < .001) in multivariate-adjusted analysis. No relationship was observed between serum 25(OH)D and waist circumference, blood pressure, glycated hemoglobin (HbA1C), blood glucose, HDL-cholesterol, and serum triglycerides. This study showed an inverse relationship between prevalence of MetSyn and serum 25(OH)D in Qatari women. Given the widespread prevalence of vitamin D deficiency in Qatar, consideration should be given to vitamin D fortification of some selected staple foods and through targeted supplementation of vitamin D in those who are at risk for cardiometabolic diseases.

Metabolic syndrome (MetSyn) is a precursor for several cardiometabolic diseases such as obesity, type-2 diabetes mellitus (T2DM), and cardiovascular diseases. Emerging evidence suggests that vitamin D deficiency links to cardiometabolic diseases through microbiota. A combination of poor vitamin D status and dysbiosis may contribute to the progression of cardiometabolic diseases. Therefore, in this review, we present the relationship among vitamin D, microbiota, and cardiometabolic diseases with a focus on MetSyn. We searched major databases for reports on vitamin D, microbiota, and MetSyn until June 2022. We reviewed 13 reports on the relation between vitamin D and MetSyn (6 randomized controlled and 7 cross-sectional studies) and 6 reports on the effect of vitamin D on the gut microbiome. Adequate vitamin D status has a beneficial effect on gut microbiota, therefore preventing the progression of MetSyn. Further, well-controlled studies are needed for a better understanding of the mechanisms of action involving vitamin D and microbiota in the pathogenesis of cardiometabolic diseases.