Supermarket chain Kroger said Wednesday that it is buying online vitamin seller Vitacost.com in a deal the company says is valued at $280 million.

Kroger said Vitacost.com will help it expand online and give it access to Vitacost.com's shipping network and two distribution centers.

Cincinnati-based Kroger said it will pay $8 per share in cash for Vitacost.com, a 27% premium of its closing price of $6.28 Tuesday. The total purchasing price includes stock warrants and options. Vitacost.com, which is based in Boca Raton, Fla., will operate as a subsidiary of Kroger.

The deal is expected to close in the third quarter.

Kroger said Vitacost.com sells 45,000 products, including minerals, herbs, supplements and organic foods, to about 2.3 million customers. Vitacost.com reported revenue of $382.7 million last year.

"Vitacost.com's core focus on healthy living products is complementary to our fast-growing natural foods business," said Kroger CEO Rodney McMullen.

Kroger Co. runs more than 2,600 supermarkets around the country, including City Market, Dillons and Ralphs stores.

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