Black sesame seeds are an excellent source of magnesium and calcium. A 1/4 cup serving of provides 126 mg of magnesium, or 32 percent of the Recommended Daily Value (DV), and 351 mg of calcium (35 percent of the DV). That's slightly more than you find in a cup of milk, however, the calcium is located in the hull of the seeds, so hulled versions offer much less calcium.
Sesame seeds may be the oldest condiment known to man. Not only are sesame seeds an excellent source of copper and a very good source of manganese, but they are also a good source of calcium, magnesium, iron, phosphorus, vitamin B1, zinc, molybdenum, selenium, and dietary fiber. In addition to these important nutrients, sesame seeds contain two unique substances: sesamin and sesamolin. Both of these substances belong to a group of special beneficial fibers called lignans, and have been shown to have a cholesterol-lowering effect in humans, and to prevent high blood pressure and increase vitamin E supplies in animals. Sesamin has also been found to protect the liver from oxidative damage. Source: Whfoods.org