# Effects of Vitamin D3 Supplementation on Inflammatory Markers in Overweight and Obese Children and Adolescents: A Systematic Review

## TL;DR

This study reviews the effects of vitamin D3 on inflammation in overweight and obese children, finding mixed results with a decrease in leptin levels.

## Contribution

The novel contribution is a systematic review focusing exclusively on RCTs in children and adolescents.

## Key findings

- Vitamin D3 supplementation did not change CRP, IL-6, or TNF-α levels.
- Vitamin D3 led to a decrease in leptin levels.
- Only two RCTs met inclusion criteria, highlighting a need for more research.

## Abstract

Obesity-related low-grade inflammation is a significant factor responsible for the development of metabolic syndrome and chronic diseases, which can begin even in early childhood. Recently, there has been growing interest in the impact of vitamin D3 supplementation on inflammatory markers in overweight and obese individuals; however, findings remain inconsistent. Therefore, we aimed to conduct a systematic review to assess the effects of vitamin D3 supplementation on inflammatory markers in overweight and obese children and adolescents, focused exclusively on the analysis of randomized controlled trials (RCTs) identified by searching PubMed, EMBASE, and Cochrane Library. The results of this study were synthesized and reported following the PRISMA statement. A total of 294 citations were identified through electronic literature searches, of which two RCTs were finally included in our systematic review. We found that vitamin D3 supplementation did not affect the changes in C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), but led to a decrease in leptin levels. The small number of studies meeting the inclusion criteria for our systematic review limits the value of the presented results, but also indicates the need for in-depth research on this topic.