Headaches during your period may be due to the fluctuation in hormone levels, low iron (from loss of blood), dehydration, or stress.
If headaches occur on a monthly basis, work with your endocrinologist or OB/GYN to find a solution. If you have an unusually heavy menstrual cycle, speak with your physician about taking an iron supplement. You can also increase your intake of iron rich foods at this time, which include animal sources (red meat and poultry), fish (salmon and tuna), as well as plant sources (beans, tofu, and pumpkin seeds).
If dehydration is causing your headaches, be sure to consume enough fluids to meet your daily hydration needs. According to the Institute of Medicine, women require 2.7 liters of fluids (90 ounces) daily, 20% of which can come from hydrating foods, like fruits and vegetables.