The Hustle According to marketers, chromium supplements can help you lose weight, boost metabolism, pack on muscle and fight heart disease. Some preliminary research suggests that chromium can help regulate blood sugar and improve insulin sensitivity, to the benefit of people with or at risk of type 2 diabetes. Annual sales of chromium products rose from $65 million in 1996 to $106 million in 2003, according to Nutrition Business Journal. Chromium picolinate is the most common type.

What's the Science Say? Scientific support for the weight-loss and muscle-building claims is scant. Some studies have suggested, though, that chromium may help ward off heart disease, particularly among people with diabetes or pre-diabetic conditions. As for blood sugar regulation, the studies have been too small or inadequately designed to conclusively determine benefits, said Rebecca Costello, deputy director of the Office of Dietary Supplements at the National Institutes of Health (NIH). Chromium is difficult to measure in the body, and nobody's figured out what exactly it does once it's there.

Is It Safe? Costello said there's little evidence to suggest dietary chromium taken in the typical dosage (50 to 200 micrograms) does any harm. Extremely high doses could damage kidneys or even chromosomes.

So Should I Be Popping Chromium? Hard to imagine why, but you know the drill: Talk with your doctor (particularly if you intend to take more than 200 micrograms a day). Most people apparently get all the chromium they need -- though nobody's sure just how much that is -- from their diet. It may also be in your multivitamin. And nobody knows if eating chromium-rich foods (calf liver, brewer's yeast, American cheese, wheat germ) does any good. There's no evidence that diabetes is due to a chromium deficiency.

As for muscle-building, fat-burning and all that? Ignore the hype: There's no solid that evidence chromium works. Exercise and a healthy diet do.

-- Jennifer Huget