Sales of vitamins and minerals are project-ed to grow more than 6 percent this year — to $11.2 billion, from $10.6 billion in 2008 — according to Mintel, a market research firm, and that bump may come not in spite of the economic downturn, but because of it. “Economy-conscious consumers concerned with avoiding illness, and thus avoiding sick days, turn to supplements to maintain good health,” Mintel wrote in a recent report.

“People tend to take better care of themselves when there are tough economic conditions,” said Joe Fortunato, chief executive of GNC, the vitamin and supplement retailer. A healthy diet, exercise and supplements “are a way to reduce health care costs down the road,” Mr. Fortunato said.

Revenue at GNC increased 2.5 percent in the first six months of 2009 over the same period a year ago, to $872 million from $851 million. Now GNC is hoping to reach a broader audience with a new advertising campaign focusing on women, whom the company acknowledges it has been less successful in reaching than men striving to build muscles. Ads for a new line of products for women called Wellbeing are beginning to appear in magazines including Self, Glamour, Yoga Journal and O, the Oprah Magazine, the first time GNC has placed ads in some of those women’s titles. The ads, by Arnell in New York, part of the Omnicom Group, feature black-and-white photographs of wholesome women, and resemble ads for anti-wrinkle creams or cosmetics.

The products — including be-Beautiful, which promises to revitalize skin, hair and nails, and be-Hot, which promises to “maximize the results of your workout” — are packaged in pastel containers, with pills that also are pink or lavender. Those pills are smaller than the norm for GNC, and have a flavored coating, since company research found a common complaint among women was that vitamins were unpleasant to swallow.

The goal was to “create a brand that looks like it was designed for women, by women,” said Beth J. Kaplan, president and chief merchandising and marketing officer at GNC. Containers have a clear window so women can glimpse pills that are “smaller and colored and really quite pretty,” Ms. Kaplan said.

General Nutrition Centers — first called Lack-zoom — began as a small chain in Pittsburgh in 1935 selling yogurt, honey and grains. Today it has more than 6,700 locations internationally, about 5,300 in the United States, including 1,756 store-within-a-store locations at Rite Aid drugstores.

Mr. Fortunato said that as little as 6 percent of revenue was from basic vitamins like A or C, while the strongest sellers were proprietary blends, many offering nothing short of physical transformation. Different formulas, for example, promise weight gain, weight loss and weight maintenance.

Mintel said that “a dominant trend in the marketing of vitamins and minerals is advertising that spotlights genderspecific goals,” reporting that products for women have grown the most sharply, with 86 “female-related” supplements introduced in 2008, more than double the 36 in 2007.

According to GNC, while about half of its cur-rent customers are women, they often are buying items for their families rather than for themselves. Along with trying to woo women with new products, it is redesigning stores with them in mind. A concept store it calls the “prototype for the future,” also designed by Arnell, opened recently at the Ross Park Mall in suburban Pittsburgh. At 3,000 square feet, the store is considerably larger than the typical 1,300-square-foot GNC outlet, and it features brightly colored display cases and photo-graphs on the walls of women doing yoga, men lifting barbells and close-ups of pastel-colored pills.

The goal of the new design is to draw women, yet not be off-putting to men. “Men are mission-oriented in how they shop,” Ms. Kaplan said. “They come into a store very focused, and they know what they want — they may ask a few questions, but they’re very goal-oriented.” Women, on the other hand, “are more about the shopping experience — they want to look, browse, spend some time and they tend to be less goal oriented,” she said. “We’ve opened up the space enough so that men can be goal oriented and women can spend some time browsing.”

What is “a bit of a high-wire act,” Ms. Kaplan said, is attracting new female customers while not alienating the males by being froufrou. GNC is watching the new store closely, and after tweaking the design will reconfigure stores elsewhere, but it declined to give a time frame for doing so.

In 1995, the company redesigned about 30 of its stores as “Live Well” environments, named for the slogan it still uses today, but those stores neither lived nor did well.

“They were 3,500 square feet, and they had hand-cut soaps and fragrances and waterfalls in the middle of the stores,” said Mr. Fortunato. “They were aesthetically pleasing stores for females, but they really shut off the sports fitness consumer.”