Michael Tercha / Chicago Tribune
How eating calcium helps: Found in a variety of sources (nondairy included), calcium is often paired with Vitamin D to help regulate mood fluctuations attributed to PMS. Since estrogen plays a large role in calcium production, calcium consumption may improve PMS-related depression.
Recommended Daily Allowance, or RDA: 1,000 mg per day for adults
Collard greens, frozen (1 cup): 357 mg