It's a good thing for Martek Biosciences (NASDAQ:MATK) that babies have to eat no matter what the economy's like, because with Americans watching their wallets, it looks like they're skipping the health-food store.

Revenue at Martek, which makes nutritional supplements, was up 13.6% for its third quarter, led by 12% growth in sales of its DHA supplement to baby formula makers all over the world. This segment makes up the lion's share of total revenue -- about 85%. Also, sales of additions to other foods and beverages, like Starbucks' (NASDAQ:SBUX) muffins, J.M. Smucker's (NYSE:SJM) canola oil, and General Mills' (NYSE:GIS) yogurt, were up a nice 32%. Finally, revenue from contract manufacturing was up 46%, but don't get too excited: The category tends to be lumpy and is up just 6.8% over the past nine months.

More impressively, Martek was able to turn that 13.6% increase in the top line into a 47% boost in earnings per share, despite the basic share count increasing 2.3%. Increased activity at the company's manufacturing plants helped push gross margins up 300 basis points to 41.5%. That's quite impressive, but the company thinks it'll be able to squeeze out even more productivity gains next year. There were no restructuring charges or interest expense -- now that Martek has paid off all (or the majority of) its debt -- also helping to boost the bottom-line comparisons.

Considering the strong quarter, Martek raised its full-year guidance and said it now expects revenue to be 14% to 15% better than last year and earnings per share of $1.06 to $1.09. Martek is trading at a premium to competitors GlaxoSmithKline (NYSE:GSK) and Archer-Daniels-Midland (NYSE:ADM), but if it's able to keep up this steady double-digit growth while improving margins, it should have no problem supporting that higher valuation.

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Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. The Fool has a disclosure policy.