text: The notion of chromium as a potential regulator of glucose metabolism began in the 1950s when Walter Mertz and his co-workers performed a series of experiments controlling the diet of rats. The experimenters subjected the rats to a chromium deficient diet, and witnessed an inability of the organisms to respond effectively to increased levels of glucose within the blood. They then included "acid-hydrolyzed porcine kidney and Brewers yeast" in the diet of these rats, and found that the rats were now able to effectively metabolize glucose. Both the porcine kidney and Brewers yeast were rich in chromium, and so it was from these findings that began the study of chromium as a regulator of blood glucose.
  The idea of chromium being used for the treatment of type II diabetes was first sparked in the 1970s. A patient receiving total parenteral nutrition (TPN) had developed "severe signs of diabetes", and was administered chromium supplements based on previous studies that proved the effectiveness of this metal in modulating blood glucose levels. The patient was administered chromium for a total of two weeks, and by the end of this time-period, their ability to metabolize glucose had increased significantly; they also now required less insulin ("exogenous insulin requirements decreased from 45 units/day to none"). It was these experiments that were performed in the 1950s and 1970s that paved the foundation for future studies on chromium and diabetes.
  In 2005, the U.S. Food and Drug Administration approved a Qualified Health Claim for chromium picolinate with a requirement for very specific label wording: "One small study suggests that chromium picolinate may reduce the risk of insulin resistance, and therefore possibly may reduce the risk of type 2 diabetes. FDA concludes, however, that the existence of such a relationship between chromium picolinate and either insulin resistance or type 2 diabetes is highly uncertain." In 2010, chromium(III) picolinate was approved by Health Canada to be used in dietary supplements. Approved labeling statements included: "...provides support for healthy glucose metabolism." The European Food Safety Authority (EFSA) approved claims in 2010 that chromium contributed to normal macronutrient metabolism and maintenance of normal blood glucose concentration.
  A 2016 review of meta-analyses concluded that whereas there may be modest decreases in fasting plasma glucose or glycosylated hemoglobin that achieve statistical significance, the changes were rarely large enough to be expected to be relevant to clinical outcome.