Nutritional vitamin D reduces CRP and improves albumin in maintenance hemodialysis patients

BackgroundMicroinflammation is widespread in Maintenance hemodialysis (MHD) patients. The continuous interaction of microinflammation and malnutrition is an independent risk factor for the clinical prognosis of MHD patients. Nutritional vitamin D deficiency is closely related to chronic kidney disease inflammation, but whether correcting this deficiency can improve microinflammation in the MHD population remains unclear.MethodsStudies published up to March 1, 2025 were included. Risk of bias was assessed using the Cochrane tool. RevMan 5.4 and Stata 17 were used for analyses, with heterogeneity assessed and random-effects models applied. Key outcomes included CRP, serum albumin, TNF-α, IL-1β, immunoreactive Parathyroid Hormone (iPTH), adverse events, hypercalcemia, and hyperphosphatemia.ResultsA total of 617 patients in eight randomized controlled trials were included. The experimental group interventions were nutritional vitamin D, while those of the control group were placebo. The meta-analysis showed that the decrease in CRP in the nutritional vitamin D intervention group was significantly higher than that in the control group [MD −3.15, 95% confidence interval (CI; −4.46, −1.84), P < 0.05]. Subgroup analysis demonstrated that nutritional vitamin D supplementation not only reduced CRP in MHD patients with baseline vitamin D deficiency, but also in those with normal vitamin D baseline levels [MD −2.64, 95% CI (−4.47, −0.81), P < 0.05; MD −3.97, 95% CI (−5.78, −2.17), P < 0.05]. The increase in serum albumin in the vitamin D group was more significant than in the control group [MD 0.55, 95% CI (0.10, 1.01), P < 0.05]. iPTH decreased more significantly in the vitamin D group than in the control group [SMD −0.56, 95% CI (−1.07, −0.05), P < 0.05]. In terms of safety, the overall incidence of adverse reactions in the nutritional vitamin D group was similar to that in the control group (P = 0.09). Moreover, no significant differences were found in the incidence of hypercalcemia and hyperphosphatemia between the two groups (P = 0.15, P = 0.32).ConclusionNutritional vitamin D supplementation may improve microinflammation and nutritional status in MHD patients, with potential benefits for bone metabolism and no apparent increase in the risk of hypercalcemia or hyperphosphatemia.