NEW YORK (AP) ¿ Shares of NBTY Inc. jumped Friday after a Wedbush Morgan analyst upgraded the stock and expects the maker of nutritional products to see better gross margins and benefits from an acquisition and currency exchange rates. The stock gained $1.68, or 6.4 percent, to reach $27.75 in morning trading. Shares have traded between $12.22 and $37.26 over the past 52 weeks. The Ronkonkoma, N.Y.-based company makes and sells nutritional supplements, including vitamins. Wedbush Morgan analyst Rommel T. Dionisio upgraded shares to "Buy" from "Hold" and boosted his price target to $30 from $24 in a note to investors. He expects the company's gross margins to begin improving, after slumping because of high raw-material costs. Meanwhile, the company should see cost savings as it integrates Leiner Health Products Inc., which it bought in 2008. "In addition to favorable currency movements, we expect NBTY's core business to also generate solid momentum, driven by expanded shelf space in retailers such as Wal-Mart and Costco as well as robust high single-digit industry growth in the mass market nutritional supplement market," he said.