Effects of niacin-bound chromium supplementation on body composition in overweight African-American women

Aim: This pilot study was designed to determine whether 600 mu g niacin-bound chromium ingested daily over 2 months by African-American women undergoing a modest dietary and exercise regimen influences weight loss and body composition. Methods: Twenty overweight African-American women, engaged in a modest diet-exercise regimen, participated in a randomized, double-blinded, placebo-controlled, crossover study. They received placebo three times a day (t.i.d.) during the control period and niacin-bound chromium, 200 mu g t.i.d., during the verum period. Control and verum periods were each 2 months in duration. One-half received placebo first (group 1), the other half received chromium first (group 2). Body weights (b.w.) and blood chemistries were measured by routine clinical methodology. Fat and nonfat body masses were estimated using bioelectrical impedance (electrolipography). Results: In the first group of 10 women receiving niacin-bound chromium after the placebo period (group 1), b.w. loss was essentially the same, but fat loss was significantly greater and non-fat body mass loss significantly less with chromium intake. In contrast to the previous findings, there was a significantly greater loss of fat in the placebo compared to the verum period in the second group of eight women who received chromium first (group 2). Blood chemistries were not affected by intake of chromium for 2 months. Conclusions: Niacin-bound chromium given to modestly dieting-exercising African-American women caused a significant loss of fat and sparing of muscle compared to placebo. Once chromium was given at these dose levels, there was a 'carry-over' effect. Blood chemistries revealed no significant adverse effects from the ingestion of 600 mu g of niacin-bound chromium daily over 2 months.