Tissue and subcellular distribution of chromium picolinate with time after entering the bloodstream

Chromium picolinate, [Cr(pic)(3)], is a popular nutritional supplement; however, the fate of the complex in vivo has not previously been established. Consequently, rats were administered [51Cr(pic)(3)] intravenously and the fate of the radiolabel in the urine, blood plasma, tissues, and subcellular components of hepatocytes was followed for the first 24 h after injection. The supplement leaves the blood stream rapidly appearing in the urine and entering tissue cells intact. Kidney, muscle, and liver possess most of the absorbed radiolabel. In hepatocytes, the radiolabel appears most rapidly in the nucleus and mitochondria, then in the cytosol, and finally in the lysosomes and microsomes. Thus, while the lifetime of the supplement in vivo is brief, it enters cells rapidly intact. The significance of the lifetime and distribution of [Cr(pic)(3)] in relationship to recent reported potential DNA damage from the supplement is discussed.