Cal-Mag Citrate Effervescent Powder is an easy-to-consume form of calcium-magnesium supplementation. The effervescent quality of citric acid increases the bioavailability of citrate mineral chelates. Cal-Mag Citrate Effervescent Powder provides 500 mg calcium and 200 mg magnesium per scoop. This ratio is especially desirable for individuals who need higher amounts of calcium but who, because of magnesium’s laxative-like character, cannot tolerate an equal amount of magnesium. One scoop also provides 500 mg of vitamin C.