Background and Objective: There is a known relationship between cardiovascular diseases and low
levels of vitamin D. Previous studies on the effects of vitamin D supplementation on triglyceride
levels, a key indicator of cardiovascular health, have shown conflicting results. This study aims to summarize
the findings of these studies. The purpose of this systematic review and meta-analysis is to investigate the
effects of vitamin D supplementation on triglyceride levels in obese children who are candidates for surgery.
Materials & Methods: This study was conducted following the PRISMA statement guidelines.
Databases searched included Scopus, Mag Iran, SID, Web of Science, PubMed, and Embase for randomized
clinical trial studies published up to the end of 2021. Both Farsi and English studies were included. Search
keywords were: cholesterol, triacylglycerol, triglyceride, heart risk, metabolic syndrome, child, adolescent,
student, school, school age, childhood, vitamin D, 25-hydroxy vitamin D.
Results: The meta-analysis revealed no significant difference in triglyceride levels at the end of the study
compared to the beginning (MD = 5.23-2.92 mg/dl, 95% CI: 59%, I2 = 0.21-2.92, P). However, high levels of
vitamin D supplementation (more than 200,000 units during the treatment period) led to a significant
decrease in triglycerides (MD = -5.08 mg/dl, 95% CI: -83.00 to -4.15, I2 = 64%, P = 0.31).
Conclusion: High levels of vitamin D supplementation significantly decrease triglyceride levels in obese
children who are candidates for surgery compared to lower levels of supplementation.