Vitamin c deficiency
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Prevalence and Global Health Impact of Vitamin C Deficiency
Vitamin C deficiency remains a significant public health concern worldwide. It is particularly common in low- and middle-income countries, but is also present in high-income regions, affecting 5–10% of adults in industrialized nations and up to 10% of the Western population 148. Certain groups, such as the elderly, institutionalized individuals, people with poor diets, alcoholics, and those with severe psychiatric illness, are at higher risk 1510. The lack of high-quality epidemiological studies in many regions means the true extent of vitamin C deficiency may be underestimated .
Causes and Risk Factors for Vitamin C Deficiency
The primary cause of vitamin C deficiency is inadequate dietary intake, often due to low consumption of fruits and vegetables 25. Other contributing factors include cultural dietary practices, environmental influences (such as climate and pollution), demographic variables (age, sex, race), socioeconomic status, body weight, pregnancy, lactation, genetic differences, smoking, and the presence of diseases like cancer or severe infections . Disease states, especially those involving inflammation or increased metabolic demand, can further deplete vitamin C levels 259.
Clinical Manifestations: Scurvy and Beyond
Severe vitamin C deficiency leads to scurvy, a condition characterized by blood vessel fragility, fatigue, gum bleeding, bruising, and, in rare cases, death . Scurvy is now rare in developed countries, but cases still occur, especially among at-risk populations . Even moderate deficiency (hypovitaminosis C) can have health consequences, including increased morbidity and mortality .
Neuropsychiatric and Cognitive Effects
Vitamin C plays a crucial role in brain health. Deficiency has been linked to depression, cognitive impairment, and, in animal studies, reduced brain development and function 3678. In older hospitalized patients, vitamin C deficiency is associated with a higher likelihood of cognitive impairment . The blood levels of vitamin C associated with these neuropsychiatric effects are higher than those required to prevent scurvy, suggesting that even mild deficiency can impact mental health .
Vitamin C Deficiency in Disease States
Patients with advanced cancer are particularly susceptible to vitamin C deficiency, which is associated with lower dietary intake, higher inflammation, and shorter survival . Infections and chronic diseases can also lower vitamin C levels due to increased metabolic needs and inflammation, further impairing immune function 259.
Immune Function and Infection Susceptibility
Vitamin C is essential for immune defense, supporting both innate and adaptive immune responses. Deficiency impairs immunity and increases susceptibility to infections. Infections, in turn, can further deplete vitamin C levels, creating a cycle of deficiency and illness . Adequate intake is necessary to maintain optimal immune function, and higher doses may be required during illness .
Conclusion
Vitamin C deficiency is more common than often recognized and can have serious health consequences, including scurvy, impaired immunity, and neuropsychiatric effects. At-risk groups include those with poor diets, chronic illnesses, and increased metabolic demands. Addressing vitamin C deficiency through improved dietary intake and targeted interventions is important for global health.
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