Vitamin C

          

               Vitamin C (ascorbic acid) is a water-soluble vitamin

          found in a variety of fruits and vegetables that is easily

          destroyed when exposed to air, heat and light.

         

               Functions: Essential for growth and maintenance of all

          cells and tissues; promotes the absorption of iron in the

          intestines; and acts as a water-soluble antioxidant in the

          body.

         

               Sources: Many fruits and vegetables, including citrus

          fruits, cantaloupe, strawberries, tomatoes, green and red

          peppers, kale, collards, mustard greens, broccoli, cabbage,

          and potatoes.

         

               Deficiency: Signs of deficiency include delayed wound

          healing; increased susceptibility to infection; and scurvy,

          a condition characterized by bleeding under the skin,

          anemia, joint tenderness and swelling, poor wound healing,

          weakness, and such oral disorders as bleeding gums, tooth

          loss, and gingivitis. However, because vitamin C sources

          are plentiful in the U.S. food supply, deficiency is rarely

          seen; it mainly occurs n infants fed cow's milk only, or in

          people whose diets lack adequate sources of vitamin C. In

          addition, cigarette smokers have lower blood levels of

          vitamin C than nonsmokers. As a consequence, the National

          Research Council recommends that smokers consume at least

          100 milligrams of vitamin C per day.

         

               Excess: High intakes of 1 gram or more per day may

          cause nausea, abdominal cramps, and diarrhea in some

          people.