Chromium
Chromium is the most controversial "essential" trace mineral. US IOM still classifies it as essential (as chromium picolinate); the European Food Safety Authority (2014) concluded there is no evidence humans require it. It's marketed heavily for blood sugar and weight loss; both claims outrun the trial data.
IOM Adequate Intake
- Adult men 19–50: 35 µg/day.
- Adult women 19–50: 25 µg/day.
- Men 51+: 30 µg/day.
- Women 51+: 20 µg/day.
- Pregnancy: 30 µg/day.
- No Tolerable Upper Intake Level — trivalent chromium (Cr³⁺) is generally considered safe up to 1,000 µg/day; hexavalent chromium (Cr⁶⁺, industrial) is toxic and carcinogenic.
Blood sugar — the picolinate claim
Chromium is presumed to potentiate insulin action. A 2007 meta-analysis of 41 studies (Balk) found chromium supplementation modestly reduced HbA1c in patients with type 2 diabetes (~0.6% reduction) but not in non-diabetics. Later trials including the 2014 chromium-in-diabetes trial were largely negative. The current ADA position: not enough evidence to recommend chromium for glycaemic control in type 2 diabetes.
Weight loss
Chromium picolinate has been marketed for weight and appetite control. A 2013 Cochrane review of 9 trials concluded any weight change was small (< 1 kg) and of doubtful clinical significance. Do not use as a weight-loss aid.
The picolinate safety debate
Chromium picolinate at 600 µg/day generated concerns about DNA damage in early in vitro studies (Stearns 1995). Later human studies have not shown clear harm at supplemental doses, but the theoretical concern about the picolinate form specifically remains. If you use chromium, chromium chloride or nicotinate forms avoid this question entirely.
Food sources
- Broccoli (½ cup): 11 µg
- Grape juice (1 cup): 8 µg
- English muffin, whole wheat: 4 µg
- Potatoes, mashed (1 cup): 3 µg
- Green beans (½ cup): 1 µg
- Beef (3 oz): 2 µg
- Wine (5 oz): 1–13 µg (highly variable)
Chromium content of food is variable and difficult to measure — one reason EFSA reached its "not essential" conclusion.