Supplements, Vitamins and Kidney

OBJECTIVE: It is expected that antioxidants contribute to slow the progression of chronic kidney disease (CKD). However, there is no data on the protective effect of dietary antioxidant vitamins on CKD. The purpose of study was to evaluate the renoprotective effect of dietary antioxidant vitamins in the general population. DESIGN AND METHODS: The study participants were 127,081 Korean adults with preserved renal function with eGFR ≥ 60 ml/min/1.73 m2 . They were categorized into three groups by tertile levels of dietary antioxidant vitamins intake including vitamins C, E, and A...

All vitamins play essential roles in various aspects of body function and systems. Patients with chronic kidney disease (CKD), including those receiving dialysis, may be at increased risk of developing vitamin deficiencies due to anorexia, poor dietary intake, protein energy wasting, restricted diet, dialysis loss, or inadequate sun exposure for vitamin D. However, clinical manifestations of most vitamin deficiencies are usually subtle or undetected in this population. Testing for circulating levels is not undertaken for most vitamins except folate, B12 , and 25-hydroxyvitamin D because assays may not be available or may be costly to perform and do not always correlate with body stores...

Vitamin A (VA, retinol) and its metabolites (commonly called retinoids) are required for the proper development of the kidney during embryogenesis, but retinoids also play key roles in the function and repair of the kidney in adults. Kidneys filter 180-200 liters of blood per day and each kidney contains approximately 1 million nephrons, which are often referred to as the 'functional units' of the kidney. Each nephron consists of a glomerulus and a series of tubules (proximal tubule, loop of Henle, distal tubule, and collecting duct) surrounded by a network of capillaries...

PURPOSE: Vitamin K deficiency and hence a high level of plasma dephosphorylated undercarboxylated matrix Gla protein (dp-ucMGP) is frequent in patients on hemodialysis. This group is recommended to restrict their potassium intake which often leads to restriction of vitamin K rich foods. A menaquinone-7 (MK-7) supplement has been shown to decrease dp-ucMGP, but it has yet to be examined if a vitamin K rich diet could be equally effective. PATIENTS AND METHODS: A prospective randomized crossover intervention trial with two arms; 6 weeks of 360 μg MK-7 tablet/day and 6 weeks of a vitamin K rich diet with a 3-week washout period in between...

This paper summarizes the biochemistry, metabolism, and dietary needs of vitamins in patients with chronic kidney disease (CKD) and kidney transplant recipients. Evidence indicates that the dietary intake, in vivo synthesis, urinary excretion or metabolism of different vitamins may be substantially altered in kidney failure. There are discrepancies in vitamin status assessment depending on whether the assay is functional or measuring the blood vitamin level. Whether vitamin supplements should be routinely prescribed for patients with CKD is controversial...

Kidney disease (KD) is characterized by the presence of elevated oxidative stress, and this is postulated as contributing to the high cardiovascular morbidity and mortality in these individuals. Chronic KD (CKD) is related to high grade inflammatory condition and pro-oxidative state that aggravates the progression of the disease by damaging primary podocytes. Liposoluble vitamins (vitamin A and E) are potent dietary antioxidants that have also anti-inflammatory and antiapoptotic functions. Vitamin deficits in CKD patients are a common issue, and multiple causes are related to them: Anorexia, dietary restrictions, food cooking methods, dialysis losses, gastrointestinal malabsorption, etc...

Vascular calcification is a major manifestation of cardiovascular disease in advanced chronic kidney disease and is inhibited by vitamin K-dependent proteins. Clinical trials of vitamin K supplementation in chronic kidney disease have failed to demonstrate benefits on vascular calcification. Recent laboratory, human, and animal studies have shown that vitamin K handling and metabolism in chronic kidney disease is complex and suggest vitamin K2 subtype supplementation in isolation is unlikely to have significant clinical impact...

Vitamin K is a fat-soluble group of vitamers consisting of phylloquinone (PK) and menaquinones (MKs). To date, only a daily reference intake for PK is set; however, in the last decade, research studying the correlation between MKs intake and improvement of health in regards to cardiovascular diseases, bone metabolism, and chronic kidney disease has been conducted. MKs are synthesised by bacteria in the fermentation process of foods, e.g., cheeses. The content and bioaccessibility of vitamin K vitamers (PK, MK-4, MK-5, MK-6, MK-7, MK-8, MK-9, and MK-10) were assessed in eight different cheese products differing in ripening time, starter culture, fat content, and water content...

BACKGROUND: Chronic kidney disease (CKD) has become a global public health problem. Accumulating evidence suggested that vitamins play important roles in the progression of CKD. METHODS: A cross-sectional study was conducted to investigate the vitamin status of patients with CKD at stage 1-5. The serum concentrations of 9 vitamins, vitamin A, B1, B2, B6, B9, B12, C, D, and E were measured by electroanalytical method with a Multi-Vitamin Analyzer. Pearson correlation and multiple linear regression between serum level of vitamins were analyzed...

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Patients affected by chronic kidney disease (CKD) or end-stage renal disease (ESRD) experience a huge cardiovascular risk and cardiovascular events represent the leading causes of death. Since traditional risk factors cannot fully explain such increased cardiovascular risk, interest in non-traditional risk factors, such as hyperhomocysteinemia and folic acid and vitamin B12 metabolism impairment, is growing. Although elevated homocysteine blood levels are often seen in patients with CKD and ESRD, whether hyperhomocysteinemia represents a reliable cardiovascular and mortality risk marker or a therapeutic target in this population is still unclear...