Hypovitaminosis C Prevalence and Risk Factors in an Acute Geriatric Unit

Vitamin C is essential for numerous biological processes as it acts as a cofactor in various hydroxylation reactions, but also as a powerful antioxidant. As humans have lost the ability to synthetize Vitamin C, this micronutrient is found exclusively in the food, and more particularly in fresh fruits and vegetables. The term 'hypovitaminosis C' refers to a plasmatic Vitamin C concentration \< 28 µmol/L. It encompasses two distinct situations, according to the severity of the deprivation: * A deeply lowered plasmatic concentration (\< 11 µmol/L) is defined as 'Vitamin C deficiency'. The resulting condition is scurvy and its well-known haemorrhagic complications, very likely to be fatal. * A less low plasmatic concentration (11-27 µmol/L) is defined as 'Vitamin C depletion'. Symptoms are polymorphic and less suggestive, especially for elderly patients. Many studies suggest a chronic Vitamin C depletion may favour the occurrence of various conditions such as cognitive impairment, psychiatric disorders, cardio-vascular diseases, or certain cancers, thereby highlighting the involvement of Vitamin C in many biological processes. The epidemiology and risk factors of hypovitaminosis C in ageing populations are poorly documented. The few studies dealing with this question are mostly retrospective, including a low number of patients, and relying on an imperfect methodology. Despite these limitations, data suggest hypovitaminosis C could concern up to 50% of the hospitalized geriatric population. Despite this probably high prevalence, hypovitaminosis C is barely diagnosed and thus rarely supplemented. This is particularly true for the elderlies who are at risk high of being Vitamin C depleted. Moreover, several risk factors have been described to be associated with Vitamin C depletion or deficiency, sometimes both. But only a few of them have been validated for the geriatric population. Thus, there is a real need for a better understanding of hypovitaminosis C epidemiolo