Increasing evidence has suggested a protective role of vitamin D on metabolic syndrome (MetS). In this study of 1790 workers, ages 18 to 69 y, an inverse trend was observed between vitamin D (25(OH)D) and MetS.The higher the vitamin D the lower the risk of Metabolic Syndrome.

So get out into the sun.

A number of other studies have shown a link between low vitamin D and diabetes and metabolic syndrome. In a study of 15,088 subjects Vitamin D levels were inversely associated with hypertension, diabetes mellitus and hypertriglyceridemia. Other cross-sectional studies have confirmed the links between vitamin D deficiency and both hypertension and diabetes. One study reported that a daily intake of 800 IU of vitamin D compared with a daily intake of less than 400 IU of vitamin D reduced the risk of type 2 diabetes by one-third. A number of studies have shown a close link between vitamin D deficiency and metabolic syndrome. Vitamin D appears to be necessary to maintain adequate apolipoprotein A-I concentrations, the main component of HDL (good) cholesterol. One study found similar results with the lowest levels of vitamin D being associated with a 31% prevalence of metabolic syndrome, compared to only 10% for people with the highest average levels. The results also showed that vitamin D blood levels were associated with HDL cholesterol levels. Each increase of 10 ng/mL in 25(OH)D was associated with an increase of 3.8 to 4.2 mg/dL in HDL-C. An increase of just 1 mg/dL increment in HDL-C is associated with a 4% to 6% reduction in coronary heart disease risk.