RE: chromium supplements
I have a little paperback book on vitamins called "Your Complete Guide to Vitamins and Supplements" by Angelo DePalma published in 1999 and re-edited in 2001. Here are some excerpts regarding chromium (all quoted directly from book...not my own rendition):
Chromium's most important function is to help regulate the amount of glucose (sugar) in the blood. Insulin plays a starring role in this fundamental biological process, by regulating the movement of glucose out of the blood and into cells. Scientists believe that insulin uses chromium as an assistant to unlock the door to the cell membrane, thus allowing glucose to enter.
Chromium supplements appear to improve blood sugar control in people with diabetes.
Recent evidence also suggests that chromium supplements might help dieters lose fat and gain lean muscle tissue.
RDA for adults: 50 to 200 mcg
Recent evidence also suggests that chromium may be an effective aid in weight loss. A three month double blind study of 122 moderately overweight individuals attempting to lose weight found that 400 mcg of chromium daily resulted in an average loss of 6.2 pounds of body fat, as opposed to 3.4 pounds in the placebo group. There was no loss of lean body mass. These results suggest that chromium can help you lose body fat without losing muscle. It may work by helping the body process its insulin more effectively.
However, in one small double blind placebo-controlled study, chromium picolinate at a dose of 400 mcg actually led to weight gain in young obese women. When combined with exercise training, chromium picolinate produced no net effect. Interestingly, 400 mcg of chromium nicotinate combined with exercise did induce weight loss.
I guess we all have to draw our own conclusions and decide if this supplement is what we need.