Vitamin C, also known as L-ascorbic acid, is a water-soluble vitamin that is naturally present in some foods, added to others, and available as a dietary supplement. Vitamin C is required for the biosynthesis of collagen, L-carnitine, and certain neurotransmitters; vitamin C is also involved in protein metabolism. Collagen is an essential component of connective tissue, which plays a vital role in wound healing. Vitamin C, thus, helps to repair and regenerate tissues. It is also an important physiological antioxidant and has been shown to regenerate other antioxidants within the body, including alpha-tocopherol (vitamin E). Vitamin C helps protect against heart disease, aid in the absorption of iron, prevent scurvy, and decrease total and LDL (“bad”) cholesterol and triglycerides. Research indicates that vitamin C may help protect against a variety of cancers by combating free radicals, and helping neutralize the effects of nitrites (preservatives found in some packaged foods that may raise the risk of certain forms of cancer). Supplemental vitamin C may also lessen the duration and symptoms of a common cold, help delay or prevent cataracts, and support healthy immune function. According to the National Institutes of Health (NIH), the recommended vitamin C daily allowance (RDA) for adults over age 19 is: 90 mg per day for men; 75 mg per day for women; 85 mg/day for pregnant women, 120 mg/day for breastfeeding women; 40 mg/day for infants 0-6 months old; 50 mg/day for infants 7-12 months old. Male teens aged between 14 and 18 years old should have 75 mg/day while female teens of the same age should only have 65 mg per day. Deficiency symptoms include fatigue, muscle weakness, joint and muscle aches, bleeding gums, and leg rashes. Prolonged deficiency can cause scurvy, a rare but potentially severe illness. When obtained from food sources and supplements in the recommended dosages, vitamin C is generally regarded as safe. Side effects are rarely reported, but include diarrhea, nausea, abdominal cramps, and other gastrointestinal symptoms. High doses of vitamin C (greater than 2,000 mg/day) may even contribute to the formation of kidney stones.