It also intends to go all-Canadian for its roast beef, chicken and meatballs by the end of the year.
The highly-successful chain, based in the United States, emphasizes fresh ingredients and low prices.
It has also promised to stop using artificial colours, flavours and preservatives by next year.
It says it has already removed artificial colours, flavours and preservatives from 28 menu items sold by its Canadian stores. It added turkey, chicken and roast beef this week.
Subway is pursuing goals that have become a huge food-industry trend, including elimination of growth promotants, antibiotics and GMOs from some products and eliminating gestation stalls for sows and cages for hens.