Holbrook-based retail chain Vitamin World Inc. has filed for bankruptcy protection and plans to close at least 51 of its 334 stores nationwide.

Vitamin World, the third-largest retailer of vitamins, nutritional supplements, sports nutrition and beauty products in the United States, filed for Chapter 11 reorganization late Monday evening in Delaware Bankruptcy Court.

The company listed liabilities — debt and other obligations — of more than $43.6 million and estimated its assets at $50 million to $100 million.

No Long Island stores are on the list to be closed.

The company will continue operating its stores, but said in court documents that it will evaluate additional leases at underperforming stores and attempt to renegotiate their rent.

“If those negotiations are unsuccessful, Debtors will be forced to reject those leases as well,” Vitamin World’s chief financial officer Frank Conley said in a declaration filed with the bankruptcy court.

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Vitamin World, which began in 1976 with a kiosk in upstate Williamsville, now sells its products, such as its Joint Soother supplement and store brand multivitamins, online and through a network of retail stores in the U.S. and its territories.

The company previously closed 45 stores and renegotiated some leases, resulting in more than $2 million in savings, court documents show.

The company’s owner, Manhattan-based private equity firm Centre Lane Partners, said in a statement Tuesday that “it will support Vitamin World through a structured Chapter 11 restructuring process to strengthen the Company’s balance sheet and position it for growth amid the current challenged retail environment.”

Centre Lane acquired Vitamin World in February 2016 for about $25 million from Ronkonkoma-based vitamin and dietary supplement company NBTY Inc., since renamed Nature’s Bounty.

After the separation from Nature’s Bounty, Vitamin World built a corporate team, established a business operating process, found new manufacturers for its private-label products, closed nearly 50 underperforming stores and laid off more than 140 people. It also sold its Holbrook headquarters in December 2016 for $16.55 million and signed a lease for the same building that expires in February 2018.

The company now has about 1,500 employees at its 334 stores, support centers and management offices, including 91 at its Holbrook headquarters.

Nature’s Bounty has been manufacturing Vitamin World’s more than 670 store-brand products as part of a two-year transition services agreement that ends in February 2018, but Vitamin World is prepared to end the agreement by Oct. 31, according to court documents.

“The supply chain migration has encountered unanticipated challenges resulting in a lack of product availability across the company’s store base,” Centre Lane said in a statement. “Centre Lane believes the bankruptcy process will help shed unprofitable stores and allow the company to complete its supply chain transition in an orderly fashion.”

Nature’s Bounty is the largest creditor with an unsecured claim of $21.53 million, court documents show. Vitamin World still owes Nature’s Bounty about $9.5 million for the sale of the company.