Many women are aware of the importance of calcium for preventing osteoporosis, but few are aware that it also benefits women who suffer from menstrual problems such as menstrual cramps (dysmenorrhea) and PMS.

Scientists are not exactly sure why calcium seems to help menstrual symptoms. One possible reason is calcium's role in maintaining normal muscle tone. Calcium-deficient muscles are more likely to be tense and prone to cramping, which can worsen menstrual cramps as well as common symptoms of PMS, such as headaches or migraines and water retention. Some studies have also found that women with higher calcium intake reported fewer mood symptoms such as irritability, anxiety, and depression, associated with PMS. 

There are many good sources of dietary calcium. The most famous is milk and other dairy products; however, there are many plant sources as well, and some have calcium that is easier for the body to absorb and use than calcium from dairy products.

Plant-based sources of calcium include:

• leafy green vegetables, including spinach, kale, and romaine lettuce
• sea vegetables, such as kelp
• cruciferous vegetables, such as broccoli and cabbage
• certain herbs, including dill, basil, cinnamon, and thyme
• blackstrap molasses
• tofu

Broth and stock made from soup bones are another excellent source of calcium. Start with cold water (slow warming improves flavor) and plan to simmer the bones for several hours in order to get maximum flavor and nutritents. Add a little vinegar to the stock to extract more calcium from the bones. 

Even if you are consuming enough dietary calcium, you may still be calcium deficient because your body needs several other vitamins and minerals to use calcium properly. One of these, magnesium, has also been associated with reduced menstrual symptoms. Consuming too much calcium in relationship to magnesium can result in poor absorption and utilization of both calcium and magnesium.

Vitamin D also aids calcium absorption. Vitamin D occurs in only a few foods, including eggs (especially those from pastured hens), fortified dairy products and orange juice, and several types of seafood, including cod, salmon, and shrimp. The best source of Vitamin D is sunshine. Expose your body to the sun for short periods (about 20 minutes per day is good) without sunscreen to encourage Vitamin D production.

Stress and high sugar consumption are known to pull calcium from your bones and decrease absorption and use of dietary calcium.