As one of the most important water-soluble non-enzymatic antioxidants, vitamin C consists of ascorbic acid and its oxidized form, dehydroascorbic acid. Vitamin C has a wide range of metabolic functions and significantly enhances cellular immunity. One of its best benefits is its ability to increase iron absorption, thus preventing problems such as iron deficiency anemia.
Compared to the general population, plasma vitamin C levels range from 30 to 60 μmol / L. Plasma levels of vitamin C in patients on hemodialysis are usually lower than in the general population, which is mainly associated with increased inflammation, anemia, oxidative stress and secondary hyperparathyroidism. Because it is excreted by the kidneys, intake above 100-200 mg / day should be restricted in patients with CKD in order to avoid oxalosis, which is an accumulation of a metabolic by-product of ascorbic acid. Many organs and tissues of the body can be affected by oxalate deposits, including the kidneys.
The supplement of vitamin C is provided by potassium-rich foods such as citrus fruits, orange juice, strawberries and broccoli, commonly limited to hemodialysis patients for whom it is important to follow a potassium-restricted diet. Loss of this vitamin is also possible during dialysis, as about a few hundred mg of it can be removed in one dialysis treatment.