Bok Choy and Sulfur
Bok choy is a member of the cabbage family, which is awesome because cabbage (and all its varieties) are extremely healthy. They tend to contain loads of sulfur, which we need for proper hormone synthesis. Consumption of sulfur-rich vegetables has also been shown to reduce inflammation and may be protective against certain carcinogens (source).
Other Nutrients in Bok Choy
Bok choy has plenty to offer aside from sulfur. It is also loaded with vitamins A and C and calcium. Not to mention that uses for bok choy are practically endless. It can be used in salads, stir-fries, soups and stews, so don’t be stingy with the green stuff.
Mark Sisson waxes a bit poetic on bok choy.