Minerals

He tablespoon of mustard seed contains about 94 milligrams of phosphorus, which your body uses along with calcium to build bones and teeth. Phosphorus is also important for waste elimination and DNA production. One serving provides 13 percent of your daily recommended phosphorus intake. The mustard seed also contains 1.1 milligrams of iron -- 14 percent of the recommended daily intake for post-menopausal women and 6 percent for pre-menopausal women -- 15 micrograms of selenium, or 27 percent of your recommended daily intake. Iron helps your red blood vessels function, while selenium activates enzymes needed for the function of your thyroid gland.