Methods: We analyzed variants in genes significant for the status of vitamin D (DHCR7/NADSYN1 rs12785878, GC rs2282679, CYP2R1 rs10741657, and VDR rs2228570), zinc (PPCDC rs2120019) and selenium (DMGDH rs17823744) in 120 Serbian adult and pediatric COVID-19 patients using allelic discrimination. The gene discussed is NADSYN1; the disease is COVID-19.