eng Enviro Research Publishers Current Research in Nutrition and Food Science Journal 2347-467X 2322-0007 2026-04-10 14 1 313 323 10.12944/CRNFSJ.14.1.21 25444 article Anabell Del Rocío Urbina-Salazar 1 Alberto Renato Inca-Torres 1 Karina Paredes Paliz 2 Juan Alejandro Neira Mosquera 3 Sungey Naynee Sanchez Llaguno 1 Jhonnatan Placido Aldas Morejon 5 Public University of Santo Domingo de los Tsáchilas - UPSDT, km 28, Santo Domingo - Quevedo road, Ecuador Department of Interdisciplinary Studies (Health Sciences), National University of Chimborazo, Riobamba, Ecuador Department of Life Sciences and Agriculture, University of the Armed Forces (ESPE), Sangolquí, Ecuador Department of Industrial and Production Sciences, State Technical University of Quevedo, Quevedo, Ecuador Department of Applied Sciences to Industry, National University of Cuyo, San Rafael, Argentina Department not specified, Pontifical Catholic University of Ecuador, Quito, Ecuador Vitamin D deficiency is a widespread public health issue linked to increased risk of autoimmune diseases. This study explored the use of mushroom stem flour, a by-product of the mushroom industry, as a functional ingredient enriched with ergosterol, a vitamin D2 precursor, and evaluated its safety and therapeutic potential. Different UV irradiation methods (UVA, UVB, and UVC) were applied to optimize ergosterol production, considering environmental variables such as exposure time, temperature, and humidity. UVB300 irradiation led to a 70% increase in ergosterol concentration compared to natural sunlight exposure (4.52 ± 0.1 µg/g p.s. vs. 2.9 ± 0.4 µg/g p.s., p<0.05), with peak levels (23.07 ± 2.14 µg/g p.s.) observed at 30 °C and 76.3% humidity. Safety was confirmed through acute and subchronic toxicity studies in rats receiving daily oral doses of 5,000 mg/kg body weight, showing no adverse clinical, biochemical, or behavioral effects over 8 weeks. In a liver injury model, supplementation with the enriched product significantly reduced ALT levels (from 6700 ± 200 UI in the control group to 2900 ± 170 UI in the UVB-treated group) and lowered the incidence of severe liver damage from 82% ± 5% to 38% ± 4%. Statistical analysis was performed using one-way ANOVA followed by Fisher’s protected LSD test (SPSS for Windows, version 10), with significance set at p<0.0533. These findings demonstrate that UVB-irradiated mushroom stem flour is a safe, natural source of vitamin D2 with notable hepatoprotective and immunomodulatory effects, supporting its potential application as a functional supplement for immune and liver health.    https://www.foodandnutritionjournal.org/volume14number1/effect-of-uv-radiation-on-ergosterol-synthesis-in-agaricus-bisporus-and-its-hepatoprotective-potential/ Agaricus bisporus Antioxidant Dietary supplements Ergosterol Vitamin-D2