Hair samples of 37 donors including 12 patients of hepatocelluar carcinoma have been examined by fluorescent X‐ray analysis using the SPring‐8, which detected many kinds of trace elements in a single hair root. Homeostasis in concentrations of Ca, Fe, Cu, Zn and Sr was found to be in consistency with their concentrations measured for the serum in a healthy case. Unusual increases of [Cu] and/or [Fe] were observed for hair of the patients by disorder of the liver function to excrete these elements due to cancer. The unique behavior observed for [Ca] is discussed in relation to the “Calcium paradox”, a phenomenon of increasing from the regulated Ca ion concentration in cytosol, which is caused by parathyroid hormone in the case of Ca deficiency due to many kinds of disease as well as insufficient intake and absorption of Ca. It is concluded that the analysis of hair is useful for screening serious diseases such as the cancer and osteoporosis. © 2004 American Institute of Physics