Vitamin DNEW2026-09

Association between vitamin D deficiency and chronic kidney disease progression: A GRADE-based dose-response systematic review and meta-analysis.

Mojtahedi Sayed Yousef, Sedighiyan Mohsen, Pourpashang Paniz — Medicine

Summary

This study reviewed many previous research papers and found a connection between lower vitamin D levels and a higher chance of chronic kidney disease (CKD) getting worse. While this link was observed, it's important to remember that this type of study doesn't prove that low vitamin D directly causes the progression or that supplements would prevent it. More research is needed to fully understand if vitamin D interventions can help kidney health.

AI-generated summary — read the original

Key points

Lower vitamin D levels are linked to a higher risk of chronic kidney disease worsening.
This association was more pronounced in studies that followed participants for five years or longer.
However, this type of study cannot prove that low vitamin D directly causes kidney disease progression.
Further research, including clinical trials, is needed to determine if vitamin D supplements can help prevent kidney decline.

What the study looked at

What question did the study ask? Researchers wanted to understand if there's a relationship between a person's vitamin D levels and how quickly their chronic kidney disease (CKD) might get worse. They specifically looked at whether lower vitamin D was associated with a higher chance of CKD progressing. How was it studied? This was a comprehensive review and analysis of eleven existing observational studies published between 1990 and 2024. The researchers combined data from these studies to get a broader picture, looking at participants' baseline vitamin D levels and how their kidney disease progressed over time. They also examined if the strength of the association changed with different vitamin D concentrations. What did it find? The combined analysis indicated that individuals with vitamin D deficiency had about a 33% higher chance of their chronic kidney disease progressing compared to those with adequate levels. Furthermore, for every 10 ng/mL decrease in vitamin D, there was an increased likelihood of progression. The association appeared stronger in studies that followed participants for longer periods (five years or more). However, the overall certainty of this evidence was rated as very low due to the nature of observational studies and significant differences between the included studies.

Dietary takeaway

While this study suggests a link between lower vitamin D and worsening kidney disease, it doesn't prove cause and effect. To support overall health, including potential kidney benefits, consider incorporating vitamin D-rich foods like fatty fish (salmon, mackerel), fortified milk, and certain mushrooms into your diet. Remember, this is one review, and more definitive research is needed before making major dietary changes or starting supplements specifically for kidney disease progression.

Abstract

BACKGROUND: This systematic review and dose-response meta-analysis aimed to evaluate the association between serum vitamin D status and chronic kidney disease (CKD) progression. METHODS: We searched PubMed, Scopus, Web of Science, and Embase for relevant observational and cohort studies published between 1990 and 2024. Eligible studies reported baseline vitamin D levels and CKD progression outcomes. We performed a random-effects meta-analysis to calculate the pooled odds ratio (OR) for CKD progression. A dose-response meta-analysis examined the relationship between serum 25-hydroxyvitamin D (25(OH)D) levels and risk, while subgroup analyses explored follow-up duration, study quality, and comorbid conditions. We assessed evidence certainty using the Grading of Recommendations Assessment, Development and Evaluation approach. RESULTS: Eleven studies met the inclusion criteria. The pooled analysis suggested that vitamin D deficiency was associated with 33% higher odds of CKD progression (OR = 1.33, 95% confidence interval [CI]: 1.06-1.67; P = .019); however, between-study heterogeneity was considerable (I-squared heterogeneity statistic [I2] = 98.2%). The pooled estimate should therefore be interpreted cautiously as an average association across heterogeneous studies. A dose-response analysis of 10 studies suggested higher odds of CKD progression per 10 ng/mL lower 25(OH)D concentration (OR = 1.18, 95% CI: 1.09-1.25), although its interpretation was limited by reconstructed category-level exposure values. Subgroup analyses showed stronger associations in studies with long-term follow-up (≥5 years; OR = 2.07, 95% CI: 1.29-3.14; P = .001) and high-quality studies (OR = 1.35, 95% CI: 1.06-1.69; P = .03). The Grading of Recommendations Assessment, Development and Evaluation assessment rated the certainty of evidence as very low for the overall association and low for the dose-response analysis, primarily because of the observational study designs and substantial between-study heterogeneity. CONCLUSION: Lower serum 25(OH)D levels were associated with higher odds of CKD progression. However, the observational nature of the evidence does not establish that routine screening or vitamin D supplementation can prevent renal function decline. Prospective studies and randomized trials are needed to clarify the clinical utility of vitamin D assessment and supplementation for renal outcomes.

View on PubMed →DOI: 10.1097/MD.0000000000050522