This study presents the main activities carried out within the VITADWASTE project, a PRIN (Progetti di Rilevante Interesse Nazionale), funded by the Italian Ministry of University Education and Research. VITADWASTE project represents an example of the recovery and valorization of biological waste, specifically fish waste. Fish waste includes byproducts such as bones, guts, heads, skin and fins, or species below the minimum conservation size and tissues not suitable for human consumption. In the VITADWASTE project, an innovative green extraction method has been developed to recover vitamin D3 from fish waste. The aim of the VITADWASTE project is to use a multidisciplinary and sustainable approach to turn biological waste into a valuable resource, based on the principles of circular economy and bioeconomy, and to create a safe and useful vitamin D3 nutraceutical product for human consumption.