Dec 20 (Reuters) - Kroger Co said on Tuesday it had put in place limits on purchases of children's pain relievers and cold medicine products, as retailers in the United States grapple with supply constraints amid surging demand.

The U.S. grocer has asked customers to limit their purchase to two pediatric pain medications and four cold and flu items, a company spokesperson said.

Kroger joins pharmacy chains CVS Health Corp and Walgreens Boots Alliance Inc, which have also limited purchases of children's pain medicines at a time when U.S. flu hospitalizations have jumped to the highest in a decade for this time of year.

CVS currently has a two-product limit on all children's pain-relief products at its pharmacy locations and online, while Walgreens had put a limit of six over-the-counter pediatric fever reducers per online transaction. (Reporting by Deborah Sophia in Bengaluru; Editing by Saumyadeb Chakrabarty)