Cal/Mag 1:1 provides calcium and magnesium in equal amounts, with 200 mg of each mineral per serving of 2 capsules. Although the most commonly recommended dietary ratio of calcium to magnesium is 2:1, magnesium depletion has become very common in the U.S. Many components of the modern lifestyle increase magnesium loss, including stress (physical or emotional), alcohol or coffee consumption, exercise, excessive sweating, and certain medications, such as birth control pills, various antibiotics, and common diuretics. These factors cause many individuals to require compensation for extra magnesium.