The 32-year-old, who broke her right arm at the start of the season and still does not have full use of her hand, lost control early in her run and crashed into the safety netting.
After a worrying moment when Vonn sat still in the netting, she got to her feet in no obvious discomfort.
Vonn said she also had been sick.
"Unfortunately after getting food poisoning and crashing today I don't feel healthy enough to safely race tomorrow so I will not be starting," she tweeted on Saturday.
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Slovenia's Ilka Stuhec won Saturday's race ahead of Elena Curtoni while several other leading contenders failed to reach the finish as the soft snow conditions again proved tricky.
It was Stuhec's sixth win of the season and helped her to close the gap on overall World Cup leader Mikaela Shiffrin who finished 11th, having pulled out of Friday's combined event along with team mate Vonn because of safety concerns about the course conditions.
Stuhec finished second in Friday's combined.
(Reporting by Martyn Herman and Andrew Both; Editing by Clare Fallon and Neville Dalton)
