At least two restaurant chains in the Washington region are eliminating trans fats from their menus — just one month after New York City health officials announced all restaurants in that city must phase out the substance known to increase the risk of heart disease.

Capitol City Brewing Co., a locally owned restaurant chain with locations in Shirlington, the District and Baltimore, will phase out trans fats from itsmenu by March. B. Smith’s, a New York-based chain with a Union Station restaurant, went trans fat-free this month, a process that involved revamping about 40 percent of its existing menu. The two restaurants appear to be some of the first in the region to voluntarily make the switch.