Vitamin D₃ Enhances Reproductive Population Expansion and Dna Yield in Caenorhabditis Elegans: A Combined Experimental and Computational Study

VVitamin D₃ is a multifunctional secosteroid regulating calcium homeostasis, immune regulation, and cellular metabolism; however, its reproductive and genomic roles in invertebrates remain largely unexplored. This study examined the effects of vitamin D₃ on population expansion and genomic DNA thermal behavior in Caenorhabditis elegans using integrated experimental and computational approaches. Synchronized L4-stage C. elegans were exposed to 1,000 IU, 2,000 IU, and 4,000 IU of vitamin D₃ per NGM plate, and population growth was monitored from Day 0 to Day 15, with image-based counts recorded during follow-up. Vitamin D₃ treatment significantly increased final worm numbers compared with controls, with the strongest population expansion observed in the 1,000 and 4,000 IU groups. Genomic DNA quantification showed the highest recovered DNA concentration at 4,000 IU (193.8 ± 102.9 µg/mL), under input-normalized extraction conditions. DSC analysis revealed treatment-dependent shifts in melting temperature and enthalpy, indicating altered thermal denaturation behavior of isolated genomic DNA rather than direct evidence of DNA damage protection. Molecular docking and 100 ns molecular dynamics simulations suggested DAF-12 as the most plausible candidate receptor for vitamin D₃ (ΔG ≈ −87.67 kcal/mol), followed by NHR-48 and NHR-8. Overall, vitamin D₃ enhanced C. elegans population expansion and altered recovered DNA yield and thermal stability-related parameters, possibly through sterol-responsive nuclear receptor pathways associated with lipid metabolism and germ-line regulation. These findings highlight a potential link between vitamin D₃ exposure, reproductive output, and DNA-associated biophysical responses in C. elegans.