Vitamin C is generally well tolerated.[1] Large doses may cause gastrointestinal discomfort, headache, trouble sleeping, and flushing of the skin.[1][3] Normal doses are safe during pregnancy.[7] The United States Institute of Medicine recommends against taking large doses.[8]
Vitamin C is an essential nutrient involved in the repair of tissue and the enzymatic production of certain neurotransmitters.[1][8] It is required for the functioning of several enzymes and is important for immune system function.[8][9] It also functions as an antioxidant.[2] Foods containing vitamin C include citrus fruits, broccoli, Brussels sprouts, raw bell peppers, and strawberries.[2] Prolonged storage or cooking may reduce vitamin C content in foods.[2]
Vitamin C was discovered in 1912, isolated in 1928, and in 1933 was the first vitamin to be chemically produced.[10] It is on the World Health Organization Model List of Essential Medicines, the most effective and safe medicines needed in a health system.[11] Vitamin C is available as a generic medication and over-the-counter drug.[1] In 2015, the wholesale cost in the developing world was less than US$0.01 per tablet.[12] Partly for its discovery, Albert Szent-Györgyi and Walter Norman Haworth were awarded 1937 Nobel Prizes in Physiology and Medicine and Chemistry, respectively.[13][14]