200–1,000 µg/day of chromium picolinate in studies.
Small improvement in glycemic control, more if there is a deficiency.
View the study (meta-analysis) →⏱ 3 min read
Chromium is a trace mineral present in small amounts in the diet (broccoli, nuts, whole grains, brewer's yeast) whose recognized biological function is to enhance the effect of insulin on cellular glucose uptake, a property that for decades has fueled its use as a supplement for diabetes and insulin resistance, with results that clinical research has since qualified relative to the initial expectations.
Unlike classic minerals such as iron or calcium, chromium has no clinically recognized dietary deficiency in the general population, and regulatory bodies have not established an official intake recommendation for trivalent chromium; hexavalent chromium (Cr6+) is industrial and carcinogenic, whereas the trivalent chromium (Cr3+) used in supplements has a very different safety profile.
The evidence on chromium and type 2 diabetes is heterogeneous: several meta-analyses have shown modest reductions in fasting blood glucose (between 5 and 20 mg/dL) and in HbA1c (0.3-0.5 points) with doses of 200-1,000 micrograms daily of chromium picolinate for 8-16 weeks, but the effect is clearly greater in people with documented deficiency or frankly poor glycemic control than in well-treated diabetic patients.
The most plausible mechanism is enhancement of post-receptor insulin signaling through the chromodulin-insulin complex, which improves the translocation of GLUT4 transporters to skeletal muscle; the effect adds to that of metformin and other oral antidiabetic drugs without producing relevant drug interactions, although the absolute magnitude of the additional benefit is modest.
In people with overweight or obesity, several trials have shown modest but significant reductions in subjective appetite, especially carbohydrate craving, with doses of 200-1,000 micrograms daily of chromium picolinate over several weeks; for body composition the effects are weaker and the results on weight loss are inconsistent, with some studies showing small losses and others showing no difference from placebo.
In atypical depression with carbohydrate craving and weight gain (a specific phenotype of depression that psychiatry has characterized well), several trials have shown significant improvements in affective symptoms and in control of carbohydrate appetite with chromium picolinate at doses of 600 micrograms daily, a curious indication but one with serious clinical data.
In polycystic ovary syndrome with insulin resistance, several small studies have shown improvements in metabolic markers and, in some cases, in menstrual regularity; in reactive hypoglycemia (a condition in which blood sugar drops excessively 2-3 hours after eating) there are interesting preliminary data, in line with the general effect on insulin sensitivity.
The doses studied range from 200 to 1,000 micrograms daily of chromium picolinate (the form with the best bioavailability), divided into one or two doses with meals to maximize absorption; other forms (nicotinate, polynicotinate, chloride) have lower or variable bioavailability, whereas brewer's yeast chromium is a natural dietary option but with non-standardized doses.
Generally well tolerated at standard doses; adverse effects are rare (mild digestive discomfort, headache); at very high doses and with prolonged use, rare cases of liver or kidney damage have been described, which makes it prudent not to exceed 1,000 µg/day without supervision; people taking antidiabetic drugs may need a dose adjustment if the effect on blood glucose is notable, especially those who are already well controlled and could experience hypoglycemia with the addition of chromium.
Information, not medical advice. Scientific evidence reflects the quality of the studies.