Vitamin C, or ascorbic acid, may also help protect and strengthen joints by preventing free radical damage to cells. The vitamin also helps form the protein in tendons, ligaments and other tissues. You can get vitamin C in fruit -- especially oranges and grapefruits -- and many vegetables.Vitamin D, which is found in fatty fish, mushrooms, and fortified dairy products, is also made in your skin in the presence of sunlight.everal vitamins and minerals have been studied for their protective effects on the joints. They include copper, selenium and vitamins C and D.