Importance of vitamin C in human health and disease

Abstract

Ascorbic acid (AsA or vitamin C) is an essential human micronutrient predominantly obtained from plants. Our primate ancestor lost its ability to synthesize AsA at a time when its diet was rich in AsA. Today, eating sufficient fruits and vegetables to obtain more than the minimum level of AsA consistently is a challenge for many people. Research is revealing the importance of AsA in human health well beyond merely preventing scurvy. AsA acts as a cofactor for enzymes involved in epigenetic programming. The link between AsA and epigenetics has profound implications on how dietary AsA might impact on human health. Epigenetic programming plays a crucial role in embryonic development, the progression of cancer, and age-related diseases and there is evidence AsA influences all of these processes. AsA also plays a key role in regulating iron uptake. Iron deficiency anaemia is the most common and widespread micronutrient deficiency, affecting around two billion people worldwide, especially women and children. While it has been long known that AsA enhances uptake of non-haem iron from food, recent studies have found that rather than simply acting in the gut to convert iron into a form that is more readily absorbed, AsA is likely a key regulator of cellular iron uptake. Increased understanding of the various cellular roles of AsA is revealing that regularly obtaining sufficient dietary AsA is important for long-term human health. Enhancing the AsA contents of crop plants has the potential to improve the uptake of dietary AsA and improve human health.