Vikings running back Adrian Peterson, who was downgraded to questionable because of an “illness” on Saturday, said he became ill after eating enough shrimp to upset his stomach enough to make him vomit. Peterson has a shellfish allergy.

“I didn’t have any type of reaction, but I’m sure it contributed to how my stomach was feeling,” said Peterson, who rushed for 98 yards in the Vikings’ 28-19 win over the Lions in Detroit today. “Sometimes, I love shrimp so much that I go against the grain sometimes. I always make sure I keep an Epi Pen with me.”

Peterson laughed off a report during the telecast that said he became ill after swallowing his chewing tobacco during a rough landing in Detroit.

“Man, I’ve been dipping for the past 10 years; swallowing dip,” he said. “My body is immune to it. It doesn’t affect me at all.”

Peterson, who also had an allergic reaction to eating gumbo during training camp in 2012, also said he learned his lesson.

“Never before a game again,” he said. “It won’t happen again. I learned my lesson.”