One of the diets was unusually low in calcium and manganese , a trace mineral that s found in nuts, tea , whole-grain cereals and dried peas and beans. The same women also tried a diet that was supplemented with both minerals. It s interesting to note that the diet the researchers considered low in calcium , the one that produced the most uncomfortable menstrual periods, included about 587 milligrams of calcium per day. The high- calcium diet had about 1,336 milligrams of calcium , which is close to the amount experts recommend to prevent osteoporosis, the brittle bone disease. Just how these minerals fend off menstrual discomfort isn t clear.
Researchers know that calcium is involved in the production of prostaglandins.
It may be calcium s role in prostaglandin metabolism that s responsible for the mineral s effect on pain, says James G. Penland, Ph.D., head researcher at the Grand Forks Human Nutrition Research Center. Manganese s role is even more mysterious. We do know that manganese is involved in blood clotting, and some research shows that a low intake is associated with a heavier menstrual flow, says Dr. Penland. This is definitely an area that needs more study. The Daily Value for manganese is 2 milli grams.