BOSTON — Coming on the heels of an “extremely successful” year in 2008, the Grain Food Foundation’s public service announcement, the “Bread Trail,” gained dramatically greater exposure in 2009.

Results for the television spot from last year were announced by Jennifer Geiger, a senior account executive at Mullen, which created the p.s.a. She said more than twice as many viewers saw the spot in 2009 than in 2008.

The television spot was launched in January 2008 jointly by the G.F.F. and the March of Dimes in connection with National Folic Acid Week.

Early in 2009, the foundation called attention to the campaign’s success the year before, equating to $1.1 million in media value. The group noted that the spot was far more successful than a p.s.a. a year earlier featuring Susie Castillo, a former Miss USA.

“The Bread Trail earned more than twice as many airings on twice as many stations in three times as many markets,” the foundation said last year.

By contrast, in 2009 the media value was estimated at $4.7 million, more than quadruple the figure in 2008. The 9,052 airings and 162.3 million viewers compared with 7,724 airings and 62.4 million viewers reached in 2008.

“The p.s.a. did wonderfully on the national networks — airing on A&E, Biography, CNN Airport, CNN Headline News, History Channel, NBC Universal HD, Sleuth and USA Network,” Ms. Geiger said. “Additionally, the p.s.a. aired on 18 of the top 20 markets.

“We have re-distributed the p.s.a. for 2010, and since its re-release at the end of November, it has aired 78 times on 22 stations, with 5.4 million viewer impressions and more than $400,000 in ad value. The p.s.a. has already aired on three national networks as well as in top markets such as Boston, Atlanta and Seattle. “

The 30-second television spot features a young woman finding a trail of white bread slices as she enters her home. Curious, she follows the trail up a staircase, through hallways and to the bedroom, where she finds her husband smiling at the edge of the bed holding a tray of sandwiches. There is no dialogue during the spot, and as the woman closes the bedroom door, a narrator explains, “Even if you aren’t planning on getting pregnant now you should know that foods rich in folic acid such as white bread and leafy greens can help prevent some birth defects before you even know you’re pregnant.”

“The broadcast p.s.a. has continued to provide a tremendous return on investment and we look forward to another great year,” Ms. Geiger said.