Dietary Supplement Gluten Free Foundational Bone Support Muscle/Tendon NSF Certified for Sport An easy-to-consume calcium and magnesium supplement in an optimally absorbed form. Cal-Mag Citrate Effervescent Powder helps maintain normal bone and muscle health. It also provides vitamin C. It effervesces when mixed with water, creating optimally absorbed minerals. Thorne's Cal-Mag Citrate Effervescent Powder is NSF Certified for Sport. It's a convenient way to help maintain normal bone and muscle health. A recent analysis of a large number of previously conducted research studies on calcium and bone mass found that daily supplementation of 500-1,500 mg of a well-absorbed form of calcium promotes bone mass in adolescents, young adults, older men, and postmenopausal women. In addition to playing an essential role in maintaining normal bone density, magnesium is essential for normal cardiac rhythmicity, normal pulmonary function, and healthy blood glucose regulation. The addition of vitamin C enhances immune function and connective tissue support. Per scoop, Cal-Mag Citrate Effervescent Powder provides 500 mg each of calcium and vitamin C, and 200 mg of magnesium. The effervescence created by adding the powder to water enhances the absorption of the citrate-mineral chelates. Magnesium is present in all cells of the body and is involved in up to 600 enzymatic processes. Other body functions that require magnesium include nerve conduction, methyl-group transfer, conversion of pyridoxine to pyridoxal 5'-phosphate (the active form of vitamin B6), energy production, and muscle contraction. The ratio of calcium and magnesium in Cal-Mag Citrate Effervescent Powder is especially desirable for individuals who need a higher amount of calcium but who, because of magnesium's laxative-like characteristic, cannot tolerate an equal amount of magnesium. One scoop of Cal-Mag Citrate Effervescent Powder also provides 500 mg of vitamin C. Because an athlete needs to know that his or her supplements are trustworthy and compliant, every batch of an NSF Certified for Sport® product is tested for compliance with label claims and to ensure the absence of more than 200 substances banned by many major athletic organizations, including stimulants, narcotics, steroids, diuretics, beta-2 agents, and masking agents.