<p>Elevated blood pressure (BP) is a significant risk factor for cardiovascular diseases (CVD), which are the leading cause of morbidity and mortality. Dietary minerals such as sodium (Na) and potassium (K) play a crucial role in overall health and play a specific function in regulating blood pressure in the human body. Numerous studies have been conducted on the association between blood pressure and dietary intervention. While many nutritional intervention studies have shown adverse effects of excessive Na intake and the beneficial impact of supplemental K in humans, less is understood on Na and K tissue retention and health outcomes of such retention. The most commonly used biomarkers to study Na retention and regulation is urine Na. However, the use of urine Na concentration as an indicator of Na retention has its limitations and has been recently questioned. In-vivo neutron activation analysis (IVNAA) is a unique and powerful technique for elemental analysis in the human body that has the potential to quantify Na and K retention and monitor their bio-kinetics. This research work designed an in vivo neutron irradiation system with high sensitivity and minimal radiation dose to measure Na/K and monitor Na/K bio-kinetics. The system was characterized, tested, and validated for K measurement in mice and rats. Moreover, we developed a methodology for in vivo quantification of Na in pigs in bone and soft tissue after dietary intervention. The project's overall goal is to exploit the potential of a compact DD neutron generator-based neutron activation analysis system for in vivo quantification of Na and K in humans and small animals.</p>