Chromium

    Written by:
    Last Updated: September 10, 2023

    Chromium is a mineral that occurs naturally in the earth’s crust and is found in small amounts in a variety of foods. Chromium supplementation seems to enhance the effects of insulin in the body, leading to improvements in insulin sensitivity and blood sugar regulation in people with insulin resistance. Although chromium has historically been considered an essential nutrient for the human body, current evidence challenges this notion.

    What is chromium?

    Chromium is an element (Cr), and is commonly found as a mineral in the earth’s crust and soil (typically in trivalent or hexavalent form).[8] Trivalent chromium, Cr(III), is the form discussed on this page. It is generally considered safe and is found in various supplements and foods (e.g., grains, meats, brewer’s yeast, fruits, vegetables).[9] In contrast, hexavalent chromium, Cr(VI), is an environmental pollutant and carcinogen produced by industrial metal processing and found in exhaust fumes and cigarette smoke.[10]

    Trivalent chromium (from here on referred to as chromium) has been considered an essential trace mineral for many years, meaning that the body needs it in small amounts to function properly. However, while it has been proposed that chromium is required for the proper functioning of insulin and the metabolism of carbohydrates, proteins, and fats,[11] there is currently no global consensus as to whether chromium is truly essential for the human body.[12][7]

    What are chromium’s main benefits?

    Chromium is best known for its effects on blood sugar regulation in type 2 diabetes, but it may also have mild antioxidant,[13] anti-inflammatory,[14] and appetite-suppressing effects.[15] Even though chromium is a popular dietary supplement, the research on chromium is fairly mixed, and where benefits have been found, they tend to be small or negligible.

    Chromium seems to modestly reduce hemoglobin A1c (HbA1c), by an average of 0.54%,[1][16] and may improve insulin sensitivity, as indicated by reductions in HOMA-IR, but there are no clear effects on fasting blood glucose.[16] Notably, these benefits have not been observed in people with normal glucose tolerance.[1]

    Beyond blood sugar regulation, chromium may have slight weight loss benefits in people with overweight and obesity, possibly reducing weight, body mass index (BMI), and body fat percentage. However, these effects are small, likely have little clinical relevance, and are not consistently observed in people with type 2 diabetes.[15] Chromium may also reduce oxidative stress, as suggested by increased total antioxidant capacity and reduced malondialdehyde in people with type 2 diabetes, metabolic syndrome, non-alcoholic fatty liver disease, and polycystic ovary syndrome (PCOS), but this effect is poorly understood and also has questionable clinical relevance.[13]

    What are chromium’s main drawbacks?

    Chromium seems to be well-tolerated. Studies have generally not found side effects in those taking chromium compared to placebo, but thorough safety analyses have also not been done. Currently, the Institute of Medicine has no safe upper limit for chromium due to a lack of evidence.[6] There have been isolated case reports of anemia (low red blood cells), thrombocytopenia (low platelets), liver and kidney dysfunction, dermatitis, low blood sugar, and rhabdomyolysis (a severe type of muscle injury).[17][18][19][20][21] Some of these cases involved chromium doses exceeding 1,000 µg daily, but others were taking doses of 200–600 µg daily, which are considered to be within normal range. However, none of these side effects have been observed in clinical trials to date.

    How does chromium work?

    Chromium’s mechanisms of action are not well-understood, although it’s generally accepted that it enhances the effect of insulin and promotes glucose transport into insulin-sensitive tissues.[1][22] It is currently thought that these actions occur via a biological complex (an oligopeptide called chromodulin, also known as low-molecular weight chromium-binding substance (LMWCr)) with which chromium binds. In vitro research has found that insulin has a greater capacity to facilitate glucose metabolism in the presence of chromodulin,[23] and that the ability of chromodulin to stimulate glucose metabolism is proportional to the chromium content of the complex.[24] Chromodulin is thought to bind intracellularly to activated insulin receptors, essentially amplifying insulin signaling.[25] In terms of chromium’s weight loss effects, chromium seems to reduce appetite and food cravings. Preliminary research suggests that chromium may act directly on the brain to induce these effects, possibly by impacting neurotransmission,[15][26] but more research is needed to confirm this.

    Dosage information

    In research, chromium is generally supplemented at dosages ranging from 200–1000 µg daily. However, consistent dose-dependent responses haven’t been observed, and it’s unclear what an optimal dose of chromium might be.[1]

    Supplemental chromium is available in a variety of forms, with chromium picolinate, chromium nicotinate, chromium chloride, and chromium-enriched yeast being the most commonly studied forms. There isn’t clear evidence suggesting one form is the best. When taken orally, chromium in both food and supplements is poorly absorbed by the body, with absorption rates ranging from just 0.4% to 2.5%.[2] While it has been circulated in the literature that chromium picolinate has superior absorption, the study this is based on used unreliable methods to measure chromium levels and was funded by a manufacturer of chromium picolinate.[3] Other research suggests that chromium picolinate does not have superior bioavailability compared to other forms of supplemental chromium.[4][5][1]

    In terms of dietary requirements, in 2001 the Institute of Medicine proposed an adequate intake of chromium to be 30–35 and 20–25 µg daily for men and women, respectively. However, due to a lack of clinical research, this was based on estimated average intakes in the United States.[6] In 2014, the European Food Safety Authority claimed that it was inappropriate to suggest an adequate intake level of chromium due to a lack of evidence for the beneficial role of chromium on human health.[7]

    Frequently asked questions

    What is chromium?

    Chromium is an element commonly found in the earth's crust, primarily in trivalent (Cr(III)) and hexavalent (Cr(VI)) forms, and trivalent chromium is generally safe and present in various foods and supplements. Although it has been suggested that chromium may be essential for insulin function and metabolism, there is no global consensus on its necessity for the human body.

    Chromium is an element (Cr), and is commonly found as a mineral in the earth’s crust and soil (typically in trivalent or hexavalent form).[8] Trivalent chromium, Cr(III), is the form discussed on this page. It is generally considered safe and is found in various supplements and foods (e.g., grains, meats, brewer’s yeast, fruits, vegetables).[9] In contrast, hexavalent chromium, Cr(VI), is an environmental pollutant and carcinogen produced by industrial metal processing and found in exhaust fumes and cigarette smoke.[10]

    Trivalent chromium (from here on referred to as chromium) has been considered an essential trace mineral for many years, meaning that the body needs it in small amounts to function properly. However, while it has been proposed that chromium is required for the proper functioning of insulin and the metabolism of carbohydrates, proteins, and fats,[11] there is currently no global consensus as to whether chromium is truly essential for the human body.[12][7]

    Why is it unclear whether chromium is essential for the body?
    Quick answer:

    Chromium is considered an essential mineral due to case reports of deficiency in people who were on total parenteral nutrition, but the validity of these reports is questionable because the chromium content in TPN solutions is often undisclosed and may exceed dietary levels. Additionally, there are no definitive symptoms of chromium deficiency in humans, and research has not successfully induced deficiency in mice, which suggests that although chromium may have some pharmacological benefits, its necessity as a dietary nutrient remains unproven.

    Chromium was designated an essential mineral after several case reports of chromium deficiency in patients receiving total parenteral nutrition (TPN) (nutrition delivered intravenously).[40][41][42][43][44][45] These patients demonstrated insulin resistance and glucose intolerance that seemed to be corrected by the administration of chromium. However, the validity of these reports has been called into question. The content of chromium in the TPN solutions was not always disclosed, and when it was, the solutions actually contained chromium in amounts exceeding what would normally be consumed in the diet given the low bioavailability of oral chromium.[12] Additionally, researchers have failed to induce chromium deficiency in mice; results of these mouse trials suggest that chromium may be beneficial as a pharmacological agent but not a nutritional necessity.[46] Lastly, in humans there are no definitive symptoms of chromium deficiency and no validated ways to measure chromium in the body, making it challenging to identify a true deficiency.[9] Both blood and urine levels, which are frequently used in clinical trials, are not considered to be accurate representations of chromium stores in the body.[2] While chromium may have small benefits when taken in supplemental doses, further research would be required to establish chromium as an essential dietary nutrient.

    What are chromium’s main benefits?

    Chromium is primarily recognized for its role in blood sugar regulation, particularly in type 2 diabetes, where it may modestly lower hemoglobin A1c and improve insulin sensitivity. Additionally, it may offer mild antioxidant and anti-inflammatory effects, as well as slight weight loss benefits, though these effects are generally small and not consistently observed.

    Chromium is best known for its effects on blood sugar regulation in type 2 diabetes, but it may also have mild antioxidant,[13] anti-inflammatory,[14] and appetite-suppressing effects.[15] Even though chromium is a popular dietary supplement, the research on chromium is fairly mixed, and where benefits have been found, they tend to be small or negligible.

    Chromium seems to modestly reduce hemoglobin A1c (HbA1c), by an average of 0.54%,[1][16] and may improve insulin sensitivity, as indicated by reductions in HOMA-IR, but there are no clear effects on fasting blood glucose.[16] Notably, these benefits have not been observed in people with normal glucose tolerance.[1]

    Beyond blood sugar regulation, chromium may have slight weight loss benefits in people with overweight and obesity, possibly reducing weight, body mass index (BMI), and body fat percentage. However, these effects are small, likely have little clinical relevance, and are not consistently observed in people with type 2 diabetes.[15] Chromium may also reduce oxidative stress, as suggested by increased total antioxidant capacity and reduced malondialdehyde in people with type 2 diabetes, metabolic syndrome, non-alcoholic fatty liver disease, and polycystic ovary syndrome (PCOS), but this effect is poorly understood and also has questionable clinical relevance.[13]

    Is chromium beneficial for dyslipidemia or high blood pressure?
    Quick answer:

    Current evidence does not support the use of chromium for dyslipidemia or high blood pressure because studies have shown inconsistent results, and a 2023 review found no significant effects on lipid markers or blood pressure. Additionally, a 2022 meta-analysis indicated that chromium supplementation does not affect systolic or diastolic blood pressure.

    While some observational studies have found associations between low chromium levels and increased rates of dyslipidemia, high blood pressure, and cardiovascular disease,[27][28] these results have not been consistent[29][30] and many of these studies failed to control for dietary chromium intake.

    A 2023 umbrella review of 8 meta-analyses failed to find significant effects of chromium on various lipid markers, including triglycerides, total cholesterol, low-density lipoprotein (LDL), or high-density lipoprotein (HDL).[31] Similarly, chromium doesn’t seem to affect the level of apolipoproteins A or B.[32] The reported effects of chromium on blood pressure have been mixed,[33][11] but a 2022 meta-analysis did not find any effect of chromium supplementation on systolic or diastolic blood pressure.[11] Overall, current evidence does not support the use of chromium for dyslipidemia or high blood pressure.

    Is chromium beneficial for polycystic ovary syndrome (PCOS)?
    Quick answer:

    Chromium is of interest for polycystic ovary syndrome (PCOS) due to its potential to reduce insulin resistance, but it does not significantly affect BMI, fasting blood sugar, or lipid profiles. Additionally, there is insufficient evidence to support its use for PCOS, and some studies suggest that it may increase testosterone levels, which could be detrimental.

    PCOS is associated with insulin resistance, type 2 diabetes, obesity, and dyslipidemia, which has made chromium a supplement of interest for PCOS. While chromium does seem to reduce markers of insulin resistance (HOMA-IR) in people with PCOS, there is no obvious effect on BMI, fasting blood sugar or insulin, or lipid profiles. Additionally, there is some evidence that chromium supplementation may actually increase levels of testosterone (a negative effect in PCOS),[34] but this has not consistently been found.[35] Overall, there is insufficient evidence to support the use of chromium for PCOS.

    Does chromium improve athletic performance?
    Quick answer:

    Chromium has not shown any benefits in improving athletic performance, and studies have generally yielded null results across various parameters. Additionally, most trials have been short in duration, which meant that long-term effects remain unknown.

    Chromium has failed to demonstrate a benefit in athletic performance, but trials have generally been short (<13 weeks), so long-term effects are unknown.[36] Studies of chromium’s impact on parameters like strength and power,[37][38] body composition,[39][37][38] muscle fiber type,[37][38] or exercise capacity[39] have generally produced null results.

    What are chromium’s main drawbacks?

    Chromium is generally well tolerated, and few side effects have been reported compared to placebo, but thorough safety analyses are lacking. Isolated case reports have noted issues such as anemia and liver dysfunction, sometimes at daily doses exceeding 1,000 µg, though these side effects have not been observed in clinical trials.

    Chromium seems to be well-tolerated. Studies have generally not found side effects in those taking chromium compared to placebo, but thorough safety analyses have also not been done. Currently, the Institute of Medicine has no safe upper limit for chromium due to a lack of evidence.[6] There have been isolated case reports of anemia (low red blood cells), thrombocytopenia (low platelets), liver and kidney dysfunction, dermatitis, low blood sugar, and rhabdomyolysis (a severe type of muscle injury).[17][18][19][20][21] Some of these cases involved chromium doses exceeding 1,000 µg daily, but others were taking doses of 200–600 µg daily, which are considered to be within normal range. However, none of these side effects have been observed in clinical trials to date.

    How does chromium work?

    Chromium enhances insulin's effects and promotes glucose transport into insulin-sensitive tissues, likely through its binding to a biological complex called chromodulin, which amplifies insulin signaling. Additionally, chromium may reduce appetite and food cravings, potentially by affecting neurotransmission in the brain, though further research is needed to confirm this.

    Chromium’s mechanisms of action are not well-understood, although it’s generally accepted that it enhances the effect of insulin and promotes glucose transport into insulin-sensitive tissues.[1][22] It is currently thought that these actions occur via a biological complex (an oligopeptide called chromodulin, also known as low-molecular weight chromium-binding substance (LMWCr)) with which chromium binds. In vitro research has found that insulin has a greater capacity to facilitate glucose metabolism in the presence of chromodulin,[23] and that the ability of chromodulin to stimulate glucose metabolism is proportional to the chromium content of the complex.[24] Chromodulin is thought to bind intracellularly to activated insulin receptors, essentially amplifying insulin signaling.[25] In terms of chromium’s weight loss effects, chromium seems to reduce appetite and food cravings. Preliminary research suggests that chromium may act directly on the brain to induce these effects, possibly by impacting neurotransmission,[15][26] but more research is needed to confirm this.

    Update History

    Research Breakdown