Chromium is the central atom in the "glucose tolerance factor" (GTF), a hormone like compound that works with insulin to transport glucose, the body's quickest fuel out of the blood and into the cells.
With chromium present in the diet, the intestines can produce GTF. When this function (GTF) is not working properly, the cells resist insulin and do not properly absorb the glucose needed for energy.
The liver also needs chromium to manufacture fatty acids, lecithin, cholesterol and lipoproteins. Without chromium, blood fats tend to rise because the liver cannot filter them out.