The Washington, D.C., based private equity company said Friday that it has completed its purchase of NBTY for $3.8 billion in cash.
The shareholder vote in favor of the sale was tallied at 79.6 percent of a total of more than 50 million shares outstanding.
NBTY makes such well-known brands as Nature's Bounty, MET-Rx and Solgar nutritional supplements.
The board of NBTY in July approved the buyout, subject to shareholder approval.
The deal amounted to $55 a share for investors, a 47 percent premium over the company's closing price on the day the offer was disclosed.
The company is the Island's sixth-largest in terms of sales, with revenue of $2.6 billion in its most recent fiscal year earnings report. It has about 2,000 employees on Long Island and about 14,000 worldwide.