“Love, Loss and What I Wore” will end its unusually long Off Broadway run at the end of March, soon after the production hits its 1,000th perf.The play, penned by Nora and Delia Ephron and performed by a rotating roster of actresses, already has spawned a national tour — now playing in Detroit — as well as international incarnations. Successful commercial productions have become a rarity Off Broadway, with many producers lamenting the inhospitable economics of sustaining a show in Off Broadway’s smaller venues. Budget for “Love, Loss” was kept in check in part by a scaled down, staged-reading style production that also helped limit actor prep and rehearsal requirements. In addition, the subject matter is targeted squarely at the prime theatergoing demo of older women. Based on a book by Ilene Beckerman, “Love, Loss” is a collection of stories organized around the stages of a woman’s life and the clothes worn during each phase. Actresses who have played stints in the Off Broadway staging include Kristin Chenoweth, Carol Kane, Jane Lynch, Brooke Shields and Cobie Smulders. Helmed by Karen Carpenter and produced by Daryl Roth, “Love, Loss” opened Oct. 1, 2009 and recouped its $500,000 capitalization in a swift 11 weeks. When it shutters March 25, the show will have played 1,013 perfs.