In this investigation, the elements Ca and S were evaluated in a single nail clipping using compact and portable X-ray spectrometer model X-123 SDD with Ag target. Experimental conditions for current, voltage and excitation time were investigated. These analyses can be useful for a variety of applications, including nutritional and medical diagnosis, such as, the evaluation of bone dysfunctions by measurement of Ca (bone decalcification) and S for nutrition evaluations (collagen production). This analysis offers some benefits comparatively to blood and serum analyses, such as, non-invasive collection, fast analyses (minutes) and low cost. In addition, nail clippings are simple to obtain, easy to store, and easy to transport. This pilot study show a positive expectation for clinical application using in-vitro nail test.