In a letter Wednesday, Smith told Pelosi that several National Guard members in various states, including New Jersey, "have become ill due to tainted and unhealthy food from a private-sector vendor."
"Some have even reported vomiting in the Senate parking lot," he wrote. "Alarmingly, the soldiers have noted receiving almost completely raw meat, some of which, according to press reports, even contained pieces of shaved metal."
Smith asked that the company in charge of catering the food be dismissed and replaced with a new provider, "immediately."
"Furthermore, the provision of this food, whether intentional or not, warrants a thorough investigation," he wrote. "The men and women deployed here from New Jersey and elsewhere to protect the Capitol deserve meals that are absolutely safe and healthful."
Various Michigan National Guard members guarding the Capitol were also allegedly hospitalized after eating "undercooked," "raw" and "moldy" meals, as was alleged in a letter sent by Michigan House members to the Pentagon.
That letter also states that some meals contained "metal shavings."
"It is completely unacceptable that our men and women serving in Washington D.C. are being hospitalized due to the food they are being provided," the members wrote, also calling for the current food provider to be replaced.
The news comes as members of the National Guard and U.S. Capitol Police continue to keep watch over the Capitol following the Jan. 6 siege and ahead of Thursday, when Capitol police say a militia group is threatening to, again, breach the building.
Thursday, March 4, is the date that some far-right conspiracy theorists believe former President Donald Trump will return to power.
"Our Department is working with our local, state, and federal partners to stop any threats to the Capitol. We are taking the intelligence seriously. Due to the sensitive nature of this information, we cannot provide additional details at this time," Capitol Police officials said in a statement on Twitter Wednesday.
Around 5,000 National Guard troops are currently working to protect the Capitol -- both on site and around Washington, D.C, and the complex is surrounded with temporary fencing.
ABC News' Global Affairs team has reached out to the National Guard and Pentagon for comment.
ABC News' Benjamin Siegel contributed to this report.