Arthritis is characterized by pain and inflammation in the joints. This condition is not reversible although the pain can be managed using medication. Some supplements can help improve the condition. A supplement for arthritis should contain glucosamine and chondroitin sulfate. Glucosamine is a precursor of a molecule called glycosaminoglycan. This substance is essential for the growth and repair of cartilage. Chondroitin sulfate can help build and maintain healthy joints and cartilage. Another essential vitamin is vitamin D. This increases the absorption of calcium in the bones and keeps them healthy and strong. Vitamin C is not often associated with bone health. This vitamin helps in the synthesis of collagen, a component of joints. It is also a potent antioxidant. It helps counter the harmful effects of free radicals which can damage the tissues and cells of joints. A good arthritis supplement may also contain vitamin E. Like vitamin E, this nutrient also has good anti oxidant capabilities. It protects bones and joints from the destructive effects of free radicals. B vitamins are also essential for joint health. These vitamins help reduce inflammation and pain associated with arthritis. They also help promote formation of cartilage. Calcium of course is essential for bone health and formation of new cartilage. Some supplements designed for people with arthritis may contain magnesium in combination with calcium. This improves the absorption of calcium into the bones.