Chromium: Benefits, Forms, Dosing, and Side Effects

Table of Contents

• Current view (reviewed 25 October 2026)
• Key safety points
• Brad's videos on this topic
• Overview
• Forms and Bioavailability
• Evidence for Health Benefits
• Recommended Dosing
• Dietary Sources
• Safety and Side Effects
• Drug Interactions
• Frequently Asked Questions
• References

Current view (reviewed 25 October 2026)

Brad calls chromium an odd trace mineral: how it works, and what symptoms a deficiency would cause, have not yet been identified, so it cannot necessarily be considered essential (Brad, 7 Jan 2025). Recommended intakes once ranged from 11 mcg in children up to 25 to 35 mcg in healthy adults and as much as 45 mcg in breastfeeding women, but Brad notes these were cautiously retracted, not because chromium is bad, but because the evidence behind them still needs more testing (Brad, 7 Jan 2025); in fact, Europe's EFSA judged in 2014 that setting chromium intake recommendations would be inappropriate, while the US AIs from 2001 still stand ^{[1, 7]}. For trace minerals in general, he says a healthy diet provides all you need and then some, and a small amount in a multivitamin and mineral supplement is a way to be sure of getting enough (Brad, 7 Jan 2025). His main warning is megadosing: trace minerals almost all become toxic at megadose levels, so avoid supplements with hundreds of times more than you need (Brad, 7 Jan 2025).

Brad's videos on this topic

• 7 Jan 2025, Trace Minerals in Vitamins: What Are They and Is It a Fad?: chromium's role and essential status are unsettled, a healthy diet covers trace-mineral needs for most people, and megadoses are the main risk.

1. Overview

Chromium is a trace mineral found in many foods and available as a dietary supplement; whether the body needs it is debated (see below) ^[1]. In its trivalent form, chromium might play a role in carbohydrate, lipid, and protein metabolism by potentiating insulin action ^{[1, 2, 3]}. The precise mechanism has not been identified, but scientists have proposed that chromium binds to an oligopeptide to form chromodulin (LMWCr), which binds to and activates the insulin receptor ^{[1, 4, 5]}. Chromium may also have antioxidant effects ^[1].

Trivalent chromium (+3), the form found in food and supplements, differs from hexavalent chromium (+6), a toxic by-product of stainless steel and other manufacturing ^[1]. Hexavalent chromium compounds are carcinogenic when inhaled ^[3]. This article focuses entirely on trivalent chromium.

Essential Nutrient or Not?

The question of whether chromium is truly "essential" is more contested than for most trace minerals. In 2001, the Food and Nutrition Board (FNB) of the National Academies considered chromium essential based on its effects on insulin action and established Adequate Intake (AI) levels ^[2]. However, subsequent research has challenged this classification ^{[1, 8, 17]}. In 2014, the European Food Safety Authority (EFSA) concluded that no convincing evidence shows chromium is an essential nutrient and deemed it inappropriate to set chromium intake recommendations ^[7]. The FNB has not re-evaluated chromium since 2001, so its AIs remain the current US values ^[1]. The debate centers on the fact that no clearly defined chromium deficiency state has been established in healthy populations, and the original case reports of "chromium deficiency" in patients on total parenteral nutrition (TPN) have been re-evaluated and found to not provide convincing evidence of true deficiency ^{[1, 3, 7, 8, 9]}.

In three case studies published in the 1970s and 1980s, patients on long-term TPN experienced adverse metabolic and neurological effects, including hyperglycemia, glycosuria, unexplained weight loss, peripheral neuropathy, glucose intolerance, and confusion ^{[10, 11, 12]}. These effects were alleviated with pharmacologic amounts of chromium and were originally presumed to be caused by chromium deficiency. However, the studies did not adequately evaluate chromium concentrations in the TPN solutions, and scientists have concluded based on recent evaluations that these cases do not demonstrate that healthy people can develop chromium deficiency ^{[3, 7, 8, 9]}.

Currently, chromium is routinely added to TPN solutions at 10-15 mcg/day, which is much higher than the approximately 0.15 mcg/day that healthy individuals absorb from a balanced diet. The American Society for Parenteral and Enteral Nutrition has recommended research to determine whether these levels should be lowered ^{[9, 13, 14]}.

Despite this controversy, chromium remains widely included in multivitamin/mineral supplements. Most multivitamins contain 35-120 mcg of chromium, and standalone supplements commonly provide 200 to 500 mcg, with some up to 1,000 mcg ^{[1, 15]}.

Absorption and Status Assessment

In the blood, most chromium is bound to plasma proteins, particularly transferrin, with only about 5% unbound ^{[7, 16]}. Chromium accumulates mainly in the liver, spleen, soft tissue, and bone ^{[2, 7, 16]}.

Dietary chromium absorption is remarkably low, typically ranging from only 0.4% to 2.5% of ingested amounts ^{[1, 7]}. The absorption of various supplemental forms is broadly similar: chromium picolinate is absorbed at approximately 1.2%, while chromium chloride is absorbed at approximately 0.4% ^[1]. These values are comparable to the proportion of chromium absorbed from food ^[7]. Absorption is enhanced by ascorbic acid (vitamin C) and prostaglandin inhibitors such as aspirin, and inhibited by oxalate and antacids ^{[1, 18]}.

Chromium is excreted mainly in the urine ^{[1, 16]}. Urinary chromium levels reflect recent intake but are not reliable indicators of body stores ^{[3, 19]}. Hair levels might reflect past chromium intakes ^[7], and some studies have measured chromium levels in hair, sweat, serum, and toenails ^{[19, 20]}. However, no validated method for determining chromium status exists, and no clinically defined chromium deficiency state has been established in healthy populations ^{[1, 3]}.

Historical Context: The "Glucose Tolerance Factor"

Some chromium products have been marketed with the term "glucose tolerance factor" (GTF) ^[77]. The idea came from older research proposing that chromium acts within a glucose tolerance factor that helps insulin work, but attempts to identify such a factor have not produced a chemically defined compound that fits this role ^[3]. Current thinking attributes chromium's biological activity to chromodulin (LMWCr) rather than GTF ^{[4, 5]}.

2. Forms and Bioavailability

Dietary supplements contain many forms of chromium, including picolinate, nicotinate, polynicotinate, chloride and histidinate, and their absorption is broadly similar ^[1].

Comparison Table

Key Principles for Form Selection

Absorption differs little between forms. All forms are poorly absorbed (generally 0.4-2.5%), and NIH describes their absorption as similar ^{[1, 7]}.

The elemental chromium content matters. Chromium picolinate, for example, is only 12.4% elemental chromium by weight ^{[15, 22]}. The Supplement Facts label on a dietary supplement product declares the amount of elemental chromium, not the weight of the entire chromium compound ^[15].

Chromium picolinate has the most clinical trial data. The majority of intervention studies on diabetes, weight, PCOS, and lipids have used chromium picolinate, making it the most evidence-backed form ^{[1, 15, 23]}.

Glycinate's absorption advantage is shown for zinc, not chromium. A single-dose study in 12 women found zinc bisglycinate was 43.4% better absorbed than zinc gluconate ^[24]. Dr Brad Stanfield's MicroVitamin sold in the USA today (v8) includes 17.5 mcg of chromium as glycinate. Brad chose glycinate because it is an amino-acid chelate. Amino-acid forms have shown better absorption for some minerals, such as zinc, but this has not been tested for chromium. Version 9 raises chromium to 35 mcg. The UK and EU already sell v9, with chromium as picolinate. The US v9 is specified as 35 mcg of chromium glycinate and is aimed for around mid-November 2026.

Safety concerns about chromium picolinate remain unsettled. In laboratory studies, chromium picolinate generated DNA-damaging hydroxyl radicals and released chromium when processed by liver cell preparations ^{[25, 26]}, and cell and rat studies suggest it may cause oxidative DNA damage, though the meaning for people is unknown ^[74]. A 2003 review suggested other forms, such as chromium chloride, may be a better choice for this reason ^[74].

3. Evidence for Health Benefits

Type 2 Diabetes and Blood Sugar Control

Chromium has been studied most for blood sugar control in type 2 diabetes. The evidence is mixed, with the weight of evidence suggesting a modest benefit primarily in those with poor glycemic control ^[33].

The landmark 1997 Chinese trial. The most commonly cited intervention study assigned 180 adults aged 35-65 with type 2 diabetes to receive 100 mcg chromium (as chromium picolinate), 500 mcg chromium, or placebo twice daily for 4 months. At both 2 and 4 months, participants receiving 1,000 mcg/day had significantly lower fasting glucose (mean 7.1 mmol/L [128 mg/dL] vs 8.8 mmol/L [159 mg/dL] for placebo at 4 months), lower post-glucose-challenge levels (10.5 mmol/L [189 mg/dL] vs 12.3 mmol/L [222 mg/dL]), and lower HbA1c (6.6% vs 8.5%). Both 200 mcg and 1,000 mcg/day also significantly reduced fasting and post-challenge insulin concentrations (Anderson et al., Diabetes, 1997) ^[27].

Trial in poorly controlled type 2 diabetes (positive result). A 4-month single-blind trial in 71 people whose type 2 diabetes was poorly controlled (HbA1c more than 7%) and who kept taking their prescribed medicines gave 600 mcg a day of chromium picolinate or placebo. Fasting glucose fell 31.0 mg/dL with chromium and 14.0 mg/dL with placebo, post-meal glucose fell 37.0 and 11.5 mg/dL respectively, and HbA1c fell 1.90 and 1.00 points, ending lower with chromium (Paiva et al., J Trace Elem Med Biol, 2015) ^[28].

Trial in insulin-treated type 2 diabetes (negative result). A 6-month double-blind trial in adults with type 2 diabetes, an HbA1c more than 8% and insulin needs of more than 50 units a day gave placebo or 500 or 1,000 mcg a day of chromium picolinate. HbA1c fell by about 0.4% in all three groups, with no differences in secondary outcomes (46 analysed; Kleefstra et al., Diabetes Care, 2006) ^[29].

Impaired glucose tolerance trial (negative result). A randomized, placebo-controlled, double-blind trial of chromium supplementation in people with impaired glucose tolerance found that chromium did not improve glucose tolerance, insulin sensitivity, or lipid profiles (Gunton et al., Diabetes Care, 2005) ^[30].

Characterization of responders. A randomized trial in 137 participants aged 30-70 with type 2 diabetes found that 1,000 mcg of chromium picolinate daily for 24 weeks did not significantly affect insulin sensitivity, fasting glucose, or HbA1c overall. However, some participants did respond, and these "responders" had significantly lower baseline insulin sensitivity (3.98 vs 5.91 mg/kg fat-free mass/min), higher fasting glucose (8.5 vs 6.7 mmol/L [153 vs 121 mg/dL]), and higher HbA1c (7.57% vs 6.29%) than non-responders. This suggests chromium may be more likely to benefit those with more severe insulin resistance and poorer glycemic control (Cefalu et al., Metabolism, 2010) ^[31].

Comprehensive review of 8 meta-analyses (58 clinical trials). A 2019 review examined meta-analyses and systematic reviews covering 58 clinical trials lasting 3 weeks to 6 months using 1.28 to 1,000 mcg chromium daily. The most frequently used form was chromium picolinate, followed by chromium-enriched yeasts and chromium chloride. Overall, when used as adjuvant treatment, chromium lowered fasting plasma glucose and HbA1c levels slightly in people with diabetes, but the clinical significance was unclear (Costello et al., 2019) ^{[1, 15]}. A 2016 review of 20 trials in type 2 diabetes found little rationale to recommend chromium for glycemic control ^[32], and chromium supplements do not help moderate glucose levels in healthy people ^[1].

Systematic review of 41 studies (Balk et al., 2007). Almost half of the 41 trials were of poor quality. In type 2 diabetes, chromium changed HbA1c by -0.6% (95% CI -0.9 to -0.2) and fasting glucose by -1.0 mmol/L (95% CI -1.4 to -0.5) but did not change lipids, and there was no benefit in people without diabetes. Larger effects were more common in poor-quality studies (Balk et al., Diabetes Care, 2007) ^[34].

Additional meta-analyses. Several further meta-analyses in diabetes have found small effects on glycemic markers ^{[36, 37, 38]}. Abdollahi et al. (2013) found chromium lowered fasting glucose but did not affect HbA1c, lipids or BMI. Suksomboon et al. (2014) and Huang et al. (2018) both reported modest benefits as adjuvant therapy.

FDA qualified health claim. Based on the evidence, the FDA allows only the following carefully qualified statement for chromium picolinate: "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" ^{[39, 40]}.

American Diabetes Association position. In its 2010 guidelines, the ADA concluded that studies have not definitively shown that chromium supplementation benefits people with diabetes or obesity, and therefore the association cannot recommend such supplementation ^[41]. This determination was reinforced in its 2015 position statement, concluding that evidence is insufficient to support routine use of chromium supplements for glycemic control ^[42].

Synthesis. Chromium supplementation, primarily as chromium picolinate at doses of 200-1,000 mcg/day, may produce modest reductions in fasting glucose and HbA1c in some people with type 2 diabetes, particularly those with poor glycemic control and greater insulin resistance. The effect size is small (HbA1c reduction approximately 0.6% on average), the evidence quality is mixed, and the clinical significance remains debated. Chromium does not appear to benefit blood sugar in healthy, non-diabetic individuals.

Reactive Hypoglycemia

A small double-blind crossover study in women with symptoms of reactive hypoglycemia found that 200 mcg a day of chromium, as chromium chloride, for 3 months eased symptoms and raised the lowest blood glucose after a glucose load (Anderson et al., Metabolism, 1987) ^[43]. It is a single small study, so the evidence is preliminary.

Insulin Sensitivity in Non-Diabetic Individuals

An important study examined whether chromium supplementation might benefit healthy individuals. A double-blind trial gave 31 non-obese adults with normal blood sugar 500 mcg of chromium picolinate twice a day or placebo for 16 weeks. Insulin sensitivity did not change compared with placebo, but participants with the highest serum chromium had worse insulin sensitivity, and the authors urged caution in recommending the supplement (Masharani et al., BMC Endocrine Disorders, 2012) ^[44]. This raises concern about high-dose chromium in people without diabetes.

Metabolic Syndrome

Metabolic syndrome is a cluster of risk factors -- abdominal obesity, high triglycerides, low HDL cholesterol, hypertension, and elevated fasting glucose -- that raises the risk of heart disease, diabetes, and stroke ^[45]. Because insulin resistance is central to this condition, researchers have investigated whether chromium might help.

Prospective epidemiological data. A study of 3,648 adults aged 20-32 found that baseline toenail chromium concentrations were inversely associated with the incidence of metabolic syndrome over 23 years of follow-up (Bai et al., Sci Rep, 2015) ^[46].

Clinical trial (500 mcg twice daily). A trial of 63 adults aged 18-75 with metabolic syndrome who received 500 mcg chromium picolinate or placebo twice daily for 16 weeks found that chromium significantly increased acute insulin response to glucose but did not affect HbA1c, insulin sensitivity, or other measures of glucose metabolism. Chromium also had no effect on body weight or serum lipids (Iqbal et al., Metab Syndr Relat Disord, 2009) ^[47].

Chromium yeast trial. A 2018 trial of 70 adults (mean age 58) with metabolic syndrome and impaired glucose tolerance found that 300 mcg chromium daily (as chromium yeast) for 24 weeks did not affect fasting glucose, HbA1c, waist circumference, blood pressure, or lipid levels (Nussbaumerova et al., Biol Trace Elem Res, 2018) ^[48].

Combination trial. A double-blind, placebo-controlled trial gave 32 adults with metabolic syndrome 300 mg magnesium, 600 mcg chromium and 36 mg zinc per day, or placebo, for 24 weeks. Metabolic risk factors did not change, though C-reactive protein fell in the mineral group, and the design cannot separate chromium's effect from that of zinc and magnesium (Kim et al., J Trace Elem Med Biol, 2018) ^[49].

Synthesis. Limited research suggests that chromium supplements do not significantly benefit people with metabolic syndrome, despite the condition's association with insulin resistance.

Polycystic Ovary Syndrome (PCOS)

PCOS is a common endocrine disorder affecting women of reproductive age, characterized by infertility, obesity, dyslipidemia, hyperandrogenism, and elevated risks of type 2 diabetes and cardiovascular disease ^{[50, 51]}. Because insulin resistance is often central to PCOS, chromium supplementation has been studied for this population.

Meta-analysis of 7 trials (n=351). An analysis of seven trials with 351 participants administering chromium picolinate at 200-1,000 mcg daily for 8-24 weeks found no effect on fasting blood glucose, total testosterone, dehydroepiandrosterone, follicle-stimulating hormone, or luteinizing hormone levels ^[1]. However, chromium did significantly reduce BMI by 2.37 kg/m2 and free testosterone levels by 0.52 pg/mL, and reduced fasting insulin by 0.86 mIU/mL in the subgroup of studies with more than 10 participants (Fazelian et al., J Trace Elem Med Biol, 2017) ^[51].

Meta-analysis of 5 trials (n=268). A review of five trials in 268 women comparing chromium (200-1,000 mcg/day, mostly picolinate) with placebo or other treatment found no significant effect on fasting insulin or insulin sensitivity (QUICKI), but data from two trials showed chromium significantly lowered a measure of insulin resistance (HOMA-IR). One trial found chromium improved beta-cell function. The authors concluded the effect was small and of uncertain clinical relevance (Heshmati et al., Horm Metab Res, 2018) ^{[1, 53]}.

Tang meta-analysis (n=351). Tang et al. (2018) pooled six trials in 351 women: insulin resistance fell with chromium, but total and free testosterone rose, and BMI, fasting insulin, fasting glucose and lipids did not differ from control. The authors concluded chromium may not have significant benefits for women with PCOS ^[52].

Weight and metabolic outcomes. Maleki et al. (2018) conducted a systematic review concluding that chromium supplementation does not improve weight loss or metabolic and hormonal variables in PCOS patients ^[54].

Individual trial (IVF patients). Jamilian et al. (2018) gave 40 infertile women with PCOS who were candidates for IVF 200 mcg/day of chromium or placebo for 8 weeks. Chromium lowered fasting glucose, insulin and insulin resistance and reduced oxidative stress; its lipid results are under Dyslipidemia below ^[55].

Synthesis. The evidence on chromium for PCOS is mixed. One meta-analysis found small reductions in BMI, free testosterone and fasting insulin, another found testosterone rose, and effects on insulin resistance are small and of uncertain clinical significance. Larger, longer trials are needed before chromium can be recommended as a standard treatment for PCOS.

Dyslipidemia (Cholesterol and Triglycerides)

Numerous studies have found associations between poor chromium status and elevated blood cholesterol levels, prompting research into whether supplementation might improve lipid profiles ^[23].

In type 2 diabetes (negative result). A trial of 71 participants with poorly controlled type 2 diabetes found that 600 mcg/day chromium picolinate for 4 months had no effect on total cholesterol, HDL, LDL, or triglycerides (Paiva et al., J Trace Elem Med Biol, 2015) ^[28].

In PCOS (positive result). The same 8-week IVF trial in 40 infertile women with PCOS (see above) found that 200 mcg/day chromium significantly decreased serum triglycerides (-19.2 vs +8.3 mg/dL) and total cholesterol (-15.3 vs -0.6 mg/dL) compared to placebo (Jamilian et al., Biol Trace Elem Res, 2018) ^[55].

HDL and triglyceride effects (meta-analyses). Multiple meta-analyses examining chromium in diabetes and PCOS have shown no significant changes in total cholesterol or LDL cholesterol ^{[1, 35, 36]}. However, some meta-analyses have found that chromium increases HDL cholesterol by 1.73-4.64 mg/dL and decreases triglycerides by 11.71-26.57 mg/dL ^[1].

Landmark Chinese trial lipid data. In the Anderson et al. (1997) trial, total cholesterol fell after 4 months in the group taking 1,000 mcg ^[27]. Results from other higher-dose studies have been mixed ^{[1, 30]}.

Beta-blocker-induced HDL reduction. In a randomized trial in 72 men taking beta-blockers, 600 mcg a day of GTF-chromium for 8 weeks raised HDL cholesterol by 5.8 mg/dL more than placebo, an effect gone 2 months after treatment ended (Roeback et al., Ann Intern Med, 1991) ^[79].

Synthesis. Chromium supplementation does not meaningfully affect total cholesterol or LDL. There may be a modest positive effect on HDL and triglycerides, but the clinical significance is marginal. The evidence does not support using chromium specifically for dyslipidemia management.

Weight Loss and Body Composition

The hypothesis that chromium might aid weight loss is based on its role in insulin signaling: by amplifying insulin action, chromium could theoretically reduce glucose conversion to fat, increase protein synthesis, and enhance lean body mass. Some preliminary research also suggests chromium supplements might reduce food intake, hunger levels, and fat cravings ^[56].

2019 meta-analysis (21 trials, n=1,316). This analysis of adults with overweight or obesity (trial durations 9-24 weeks, chromium doses 200-1,000 mcg/day, primarily chromium picolinate) found that participants taking chromium lost significantly more weight than placebo: 0.75 kg, with a 0.40 kg/m2 reduction in BMI and 0.68% reduction in body fat percentage. There was no significant effect on waist circumference or waist-to-hip ratio (Tsang et al., Clin Obes, 2019) ^[57].

2013 Cochrane Review. This systematic review included nine trials (622 participants). Pooled across 6 trials (392 participants), chromium picolinate reduced body weight by 1.1 kg more than placebo after 12 to 16 weeks, an effect the authors called of "debatable clinical relevance", with low-quality evidence. They found no current, reliable evidence to guide firm decisions on its efficacy and safety (Tian et al., Cochrane Database Syst Rev, 2013) ^[58].

2013 systematic review and meta-analysis. Onakpoya et al. also found a small but statistically significant reduction in body weight (0.50 kg) with chromium in overweight and obese adults, and judged its clinical relevance uncertain (Obes Rev, 2013) ^[59].

Earlier meta-analysis. Pittler et al. (2003) conducted one of the first meta-analyses on chromium for weight loss, finding a small statistically significant effect that was considered of uncertain clinical relevance (Int J Obes, 2003) ^[60].

Doses in weight loss trials. Trials in the 2019 meta-analysis used 200 to 1,000 mcg a day ^[1]. Its subgroup analysis found clearer effects on weight and body fat with doses of 400 mcg a day or less and durations of 12 weeks or less ^[57].

Body composition without weight loss. Martin et al. (2006) found that chromium picolinate supplementation attenuated body weight gain and increased insulin sensitivity in subjects with type 2 diabetes, though the body composition changes were modest (Diabetes Care, 2006) ^[62].

Sports performance. A 2003 review found that more than a decade of human studies showed no effect of chromium picolinate on body composition in healthy people, even with exercise training ^[74].

Synthesis. Chromium supplementation, primarily as chromium picolinate, reduces body weight and body fat percentage to a very small but statistically significant extent (approximately 0.75 kg over 9-24 weeks). Its clinical relevance for weight management remains uncertain, and the quality of evidence is low ^{[57, 58]}. Chromium should not be relied upon as a weight loss supplement.

Cognitive Function

A small placebo-controlled trial randomly assigned 26 older adults with cognitive decline to chromium picolinate or placebo for 12 weeks. Learning rate and memory retention did not improve, but chromium reduced semantic interference on memory tests and increased activity in several brain regions on functional MRI (Krikorian et al., Nutritional Neuroscience, 2010) ^[63]. It is a single small trial, so the results are preliminary.

4. Recommended Dosing

Adequate Intakes (AIs)

The FNB established Adequate Intakes for chromium in 2001 ^[2]. These are based on observed intakes in healthy populations, not on a defined deficiency state:

*For infants from birth to age 12 months, the AIs are based on the mean chromium intakes of infants fed primarily human milk and, for older infants, complementary foods ^[2].

The FDA's Daily Value (DV) for chromium is 35 mcg for adults and children age 4 and older. This was updated in 2016 from the previous DV of 120 mcg to align with current scientific consensus ^[64].

No Tolerable Upper Intake Level (UL) has been established for chromium, due to insufficient long-term safety data. The FNB noted that caution may be warranted and that people with renal and liver disease might be susceptible to adverse effects from high intakes ^[2].

Therapeutic Dosing by Indication

For type 2 diabetes (adjunctive use): Clinical trials have typically used 200-1,000 mcg/day, mostly as chromium picolinate ^[1]. In one trial, HbA1c improved after 2 months in the group taking 1,000 mcg and was lower in both chromium groups after 4 months ^[27]. In another, patients taking chromium were told to lower their diabetes medicine doses to avoid hypoglycemia ^[65], so talk to your doctor before using chromium.

For reactive hypoglycemia: 200 mcg a day, as chromium chloride, for 3 months in one small study ^[43].

For weight management: Trials used 200-1,000 mcg/day ^[1]. The clearer effects came at 400 mcg/day or less, though evidence of clinically significant benefit is weak ^{[57, 58]}.

For general nutritional adequacy: Most multivitamin supplements provide 35-120 mcg, which is sufficient to meet the AI ^[15].

Typical Dietary Intake

A small study of 8 men and 11 women in the US found mean chromium intakes of about 29 mcg/day for women and 54 mcg/day for men ^[1]. In another study, the mean chromium content per 2,000 kcal of 22 well-balanced diets designed by nutritionists was about 27 mcg (range: 17-47 mcg) ^[67]. A 2018 dietary assessment in Northern Italy found median intake of approximately 57 mcg/day ^[68]. These findings suggest most people in the United States have chromium intakes similar to the AIs ^[1].

An analysis of NHANES III (1988-1994) data found that the median supplemental chromium intake was about 23 mcg/day among those taking supplements containing chromium ^[2].

Calcium Interaction

Antacids reduce chromium absorption ^{[1, 18]}, and many antacids contain calcium carbonate. Taking chromium and antacids at separate times may avoid this.

5. Dietary Sources

Chromium is present in many foods, including meats, grain products, fruits, vegetables, nuts, spices, brewer's yeast, beer, and wine. However, chromium amounts in foods vary widely depending on local soil and water conditions as well as agricultural and manufacturing processes ^{[3, 23, 67, 73]}. For example, the chromium content in samples of oatmeal can vary 50-fold because of growing and processing differences ^[69]. Some chromium is also transferred to foods from stainless steel equipment during food processing and from pots and pans during cooking ^{[1, 3, 67, 70]}.

Most dairy products and foods high in sugar (especially sucrose and fructose) are low in chromium ^{[2, 67]}. Diets high in simple sugars increase urinary chromium excretion, potentially worsening status ^[71].

Top Food Sources

Source: NIH ODS, based on Anderson et al., Biol Trace Elem Res 1992 and Dattilo, Nutr Today 2003 ^{[1, 67]}.

Note on data reliability: Determining chromium content of food is challenging because samples are easily contaminated by standard measurement and analysis tools. Food chromium values should be considered approximate guides rather than precise measurements ^[2].

Practical Notes on Dietary Chromium

• Processing changes chromium content. How much chromium a food holds depends on how it is grown, transported, processed and fortified ^[66].
• Cooking in stainless steel can add chromium to food through leaching from the cookware ^{[1, 70]}.
• Vitamin C enhances absorption. Consuming vitamin C-rich foods alongside chromium-containing foods may improve the already low absorption rate ^{[1, 18]}.
• Human milk contains about 0.25 mcg/L chromium, though reported values vary widely. Small studies in Europe found concentrations ranging from 0.14 to 10.8 mcg/L ^[7].
• High-sugar diets deplete chromium. Diets high in simple sugars (sucrose, fructose) increase urinary chromium losses ^[71].

6. Safety and Side Effects

General Tolerability

In trials, chromium at usual doses has not caused more adverse events than placebo ^[37]. However, a 2014 review found no studies of its long-term safety in humans, so the safety profile warrants careful consideration, particularly at higher doses ^[77].

Reported Side Effects

Side effects reported in weight-loss trials included ^[59]:

• Watery stools
• Vertigo
• Headaches
• Hives (urticaria)

In the 2013 Cochrane review, only three trials reported adverse events: two serious adverse events occurred with 1,000 mcg of chromium picolinate, one with 400 mcg and one with placebo ^[58].

Serious Adverse Effects (Case Reports)

Isolated case reports link chromium supplements to the problems below, though causality has not been established ^{[1, 74]}:

• Hematologic: Anemia, thrombocytopenia (low platelets)
• Hepatic: Liver dysfunction
• Renal: Kidney failure
• Musculoskeletal: Rhabdomyolysis (muscle breakdown)
• Other: Dermatitis, weight loss, hypoglycemia

In one case, a 33-year-old woman who took 1,200 to 2,400 mcg a day of chromium picolinate for 4 to 5 months to lose weight developed anemia, low platelets, hemolysis, liver dysfunction and kidney failure needing hemodialysis; she recovered fully ^[80]. In another, a patient developed toxic hepatitis after 5 months of chromium polynicotinate taken with plant extracts for weight loss; liver chromium was more than 10 times normal, and the hepatitis resolved after stopping ^[75].

The FNB noted that while no adverse effects have been definitively linked to high chromium intakes from food or supplements (and therefore no UL was established), caution may be warranted due to limited long-term safety data ^[2]. The FNB specifically noted that people with renal and liver disease might be susceptible to adverse effects ^[2].

Worsened Insulin Sensitivity in Healthy People

The Masharani et al. study (2012) is of particular concern for healthy individuals considering chromium supplementation. Non-obese adults with normal blood sugar given 500 mcg of chromium picolinate twice a day for 16 weeks had no improvement in insulin sensitivity, and those with the highest serum chromium had worse insulin sensitivity ^[44]. The authors advised caution in recommending chromium supplements.

Allergic Reactions

Oral chromium can cause skin reactions in people sensitised to chromate. A case report describes systemic contact dermatitis caused by oral chromium picolinate, and ingested chromate is known to cause dermatitis (Fowler, Cutis, 2000) ^[76].

DNA Damage Concerns

Two laboratory studies suggested chromium picolinate could damage DNA (Speetjens et al., Chem Res Toxicol, 1999; Kareus et al., J Hazard Mater, 2001) ^{[25, 26]}. A 2003 review judged that it probably causes oxidative DNA damage in cell and rat studies, with unknown significance for people ^[74]. In human trials, usual doses of chromium did not raise the risk of adverse events compared with placebo ^[37]. Hexavalent chromium, by contrast, is carcinogenic when inhaled ^[3].

Neurotransmitter Concerns with Picolinate Form

A 2003 review noted that possible neurological effects of chromium picolinate, good or bad, need further study ^[74].

Acute Toxicity

Swallowing a very large amount of chromium may cause serious poisoning, which is very unlikely with standard supplement doses. If someone has swallowed a large overdose, call your local emergency number (111 in NZ, 000 in Australia, 911 in the US, 999 in the UK).

Pregnancy and Lactation

Pregnant or breastfeeding women should check with their doctor before taking chromium above the Adequate Intakes (29-30 mcg/day for pregnancy, 44-45 mcg/day for lactation) ^[1].

7. Drug Interactions

Insulin

Chromium may increase insulin sensitivity ^{[1, 62]}. Taking chromium concurrently with insulin could increase the risk of hypoglycemia ^[1]. Blood sugar levels should be monitored closely if chromium supplementation is initiated in insulin-using patients. If someone with diabetes is unconscious, having a seizure, or cannot swallow safely, call your local emergency number (111 in NZ, 000 in Australia, 911 in the US, 999 in the UK). Do not give food or drink by mouth.

Metformin and Other Antidiabetes Medications

Because chromium supplementation may lower blood glucose levels, it could have an additive effect with metformin, sulfonylureas, and other antidiabetes medications, potentially increasing the risk of hypoglycemia ^{[1, 27, 28]}. Diabetic patients should consult their healthcare provider before starting chromium supplements.

Levothyroxine (Thyroid Medication)

A small study in healthy volunteers found that taking chromium picolinate together with 1 mg of levothyroxine significantly reduced levothyroxine absorption over 6 hours, compared with levothyroxine taken alone (John-Kalarickal et al., Thyroid, 2007) ^[78]. The authors advised separating the two by several hours.

Calcium Carbonate (Antacids)

Antacids reduce chromium absorption ^{[1, 18]}. Taking chromium and antacids at separate times may avoid this.

Ascorbic Acid (Vitamin C)

Vitamin C enhances chromium absorption. While this is generally considered beneficial, it could theoretically increase chromium exposure in people taking both supplements ^{[1, 18]}.

NSAIDs (Aspirin)

Prostaglandin inhibitors such as aspirin increase chromium absorption. No clinically significant adverse interaction has been documented, but it is worth noting for individuals taking high-dose aspirin along with chromium supplements ^[1].

8. Frequently Asked Questions

Does chromium help with diabetes?
Chromium picolinate at doses of 200-1,000 mcg/day may produce modest reductions in fasting glucose and HbA1c (approximately 0.6% average HbA1c reduction) in some people with type 2 diabetes, particularly those with poor glycemic control. However, the evidence is mixed, effect sizes are small, and major organizations including the American Diabetes Association do not recommend routine chromium supplementation for diabetes ^{[32, 34, 41, 42]}.

Is chromium effective for weight loss?
Chromium produces statistically significant weight loss of uncertain clinical relevance: about 0.75 kg, with a 0.68% reduction in body fat ^{[57, 58]}.

Which form of chromium is best?
Chromium picolinate has the most clinical evidence ^[1]. All forms are poorly absorbed, and NIH describes their absorption as similar ^[1]. The 43.4% absorption advantage often quoted for glycinate comes from a zinc study, not chromium ^[24].

Should healthy people take chromium supplements?
There is no evidence that chromium supplementation benefits healthy, non-diabetic individuals. In one trial, 500 mcg of chromium picolinate twice a day did not improve insulin sensitivity in healthy adults, and those with the highest blood chromium had worse insulin sensitivity ^[44]. Most people in developed countries meet the Adequate Intake through diet alone.

Is chromium safe?
No Tolerable Upper Intake Level has been set because the data are limited ^[2]. In trials, usual doses caused no more adverse events than placebo ^[37], but isolated case reports link chromium supplements to liver dysfunction, kidney failure, blood disorders and other problems, though causality is uncertain ^[1].

Can I get enough chromium from food?
Yes, for most people. Small US studies found intakes similar to the Adequate Intakes ^[1]. Food sources include grape juice, ham, whole wheat English muffins and brewer's yeast ^[1]. To achieve the doses used in diabetes trials (200-1,000 mcg/day), supplements are necessary ^[1].

Does chromium help with PCOS?
The evidence is mixed. One meta-analysis found modest reductions in BMI, free testosterone and fasting insulin, but another found testosterone rose, and others found no significant effects on insulin sensitivity or metabolic markers. The magnitude of benefit, where observed, is small and of uncertain clinical relevance ^{[51, 52, 53, 54]}.

Is chromium really an essential nutrient?
This is debated. The US Food and Nutrition Board considers it essential (2001), but the European Food Safety Authority concluded in 2014 that there is no convincing evidence of essentiality. No definitive deficiency state has been established in healthy populations ^{[2, 7, 8]}.