Chromium supplementation (0.2 ppm or 200 ppb) to swine diets has been approved by FDA and has been reported to enhance carcass leanness in barrows, but the research data are not consistent. Limited data have also indicated that chromium picolinate increases the number of pigs born live and increases sow conception rates. Chromium is considered an essential nutrient, but because the requirement is considered so low, it may not be deficient in most swine diets. No deficiency symptoms have been described in pigs. Chromium may participate in carbohydrate metabolism by enhancing the effects of the hormone insulin. Inorganic chromium is ineffective in the diets of swine, whereas other organic chromium forms have not been approved by FDA.