It is an excellent source of fiber, Vitamin C, vitamin K, vitamin A, and beta-carotene. It is a very good source of folate, calcium, and vitamin B6 as well. This member of the cabbage family has a number of different names, including Pak choy. Bok choy, Chinese celery cabbage and white mustard cabbage. Its structure looks like a squat celery, with either white or very pale green short, chunky stalks and glossy, deep green leaves.