Chromium is an element and a metal. To humans, it is also an essential micronutrient in the form of so-called trivalent chromium. Chromium also exists as divalent and hexavalent chromium but these forms are toxic. All approved chromium supplements contain trivalent chromium. The various chromium forms can bind with a variety of chemical compounds to form other substances.
Chromium contributes to the body's metabolism of macronutrients (carbohydrate, protein, and lipids). However, chromium is better known for its role in regulating blood sugar levels. Without chromium, insulin is ineffective. Chromium's influence on macronutrient metabolism and blood sugar levels are approved by the European Food Safety Authority (EFSA).
The ability to absorb and utilize elements is not very good in humans. The elements in our diet are embedded in food molecules. In food supplements, however, it is common practice to bind elements to various organic or inorganic compounds for increased absorption. Chromium is one of the nutrients which is most difficult for the body to absorb, even in situations where a person is chromium deficient. Chromium has poor bio-availability.