Subway is fortifying its bread with vitamin D and calcium as competition in the better-for-you quick-service market heats up.
The nutrients are being added to all of the breads sold at the Milford, Conn.-based sandwich chain’s more than 24,000 U.S. locations, except for English muffins and flatbread.
The bread in a six-inch sub now has 30 percent of the U.S. recommended daily intake of calcium and 20 percent of the recommended intake of vitamin D — roughly the same as a glass of milk, Subway said.
Corporate dietician Lanette Kovachi said Subway chose to add those nutrients, which are important for bone development, “because a lot of people have trouble getting them in their daily diet.”
Subway has long positioned its restaurants as better-for-you options to other quick-service establishments. It already has half a dozen “Fresh Fit” subs that are marketed as low in fat, saturated fat and cholesterol, and fewer than 400 calories.
“We’re always looking at ways we can improve the nutrition quality of our products,” Kovachi said, noting that the addition does not affect the flavor of the bread.
Subway said each sandwich made to its standard formula already provides iron, vitamin A, two full servings of vegetables, and is free of artificial trans fat.
However, Subway isn’t the only quick-service restaurant brand targeting customers seeking more healthful options.
McDonald’s recently said it would provide more nutritious meals  by reducing sodium, sugar and saturated fat across the board and replacing fries with apples as the default side dish in kids’ “Happy Meals.” The announcement came in the wake of a variety of new menu items with health halos, including additional fruit smoothie flavors and a reformulated grilled chicken.
Chick-fil-A, following the examples of McDonald’s and Starbucks, recently added oatmeal to its menu  — something that Burger King has reportedly tested.
Subway has 34,906 stores in 98 countries.