Shares of USANA Health Sciences Inc. jumped Tuesday after its chief executive and largest shareholder offered to take the company private by buying up all other shares.

Chairman and CEO Myron Wentz offered to pay $26 per share, a 25-percent premium.

Wentz, his family and others already control about 68 percent of the Utah vitamin company's stock. He made the $135 million offer Tuesday through his investment group, Gull Holdings Inc.

Wentz's offer represented a premium on USANA's $21 stock price Monday. The shares rose by $4.82 to $25.65 after the offer Tuesday. The stock was trading at $61 in 2007.

USANA sells minerals and vitamins through an army of thousands of distributors. It also sells powdered drinks, energy bars, moisturizer, shampoo and conditioner. The company has more than 900 employees, including approximately 615 people at headquarters in Salt Lake City.

Wentz said going private will save money and allow USANA's management to focus on business. His son, David, is president of USANA.

A USANA spokesman, Dan Macuga, said the company couldn't comment on the offer until it is formally submitted. USANA's board will form a committee of independent directors to evaluate the offer.

In a statement announcing his offer, Wentz referred to "pressures and distractions brought on by the public market."

In April, the company reported a 36-percent drop to $7.5 million in first-quarter profit because of higher costs and lagging North America sales.

Stock analyst Timothy Ramey of D.A. Davidson & Co. believes Wentz's offer isn't high enough, despite USANA's recent troubles.

"The sentiment has turned negative on multilevel marketers in general and USANA in particular," but the shares are worth more than $26, Ramey said.

Gull Holdings, he said, was paying around $40 when it bought 135,000 shares of USANA last year.