Glucosamine helps support cartilage and maintain structural integrity of joints and connective tissue. It is a building block for joint fluid, cartilage, ligaments, tendons, membranes and blood vessels. Schiff’s Glucosamine 2000 mg contains twice the amount of glucosamine per pill as some other leading brands. Schiff uses glucosamine hydrochloride (HCl), which has the highest potency of active glucosamine among glucosamine forms. Glucosamine hydrochloride is about 83% glucosamine, while most brands use glucosamine sulfate that is only about 65% glucosamine. Vitamin D is essential for developing healthy bones and retaining calcium and phosphorus in the body.