The Study
Can vitamin D supplementation affect cardiometabolic factors in children and adolescence with overweight and obesity? A grade-assessed systematic review and meta-analysis of randomized controlled trials
This study looked at lots of small experiments where kids took vitamin D pills or fake pills to see if it helped their health. It found that, overall, vitamin D didn’t make their weight, blood sugar, or cholesterol better — and it might even lower something good (HDL). One tiny part suggested vitamin D2 might help insulin, but we can’t trust that much because the studies were small and messy.
Analysis score
Maximum 100 for a systematic review with meta-analysis.
Where the score came from
Scientists looked at 9 studies where overweight kids took vitamin D pills to see if it helped their blood sugar and heart health.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 580 / 100
Quality score
The highest quality evidence. Systematic reviews and meta-analyses that pool randomized controlled trials, giving the most reliable summary of experimental evidence.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Lower HDL is usually bad for heart health, so this drop could be a concern—even though other numbers didn't change much.
- 2Vitamin D didn't help kids lose weight, lower blood sugar, or improve insulin.
- 3But it made 'good' cholesterol (HDL) drop by 2.16 mg/dL.
- 4One type (D2) might help insulin a little more than D3, but we're not sure.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
BMC Pediatrics
Year
2025
Authors
Amir Hossein Faghfouri, Mahsa Mahmoudinezhad, Pedram Pam, Sanaz Barazandeh, Fatemeh Faramarzi, Yousef Mohammadpour, Vali Musazadeh, Shahsanam Gheibi
Related Content
Claims (6)
In children aged 10–18 who are overweight or obese and have low vitamin D levels, taking 1000–2000 IU of vitamin D3 daily for six months lowers fasting glucose and blood pressure and increases insulin sensitivity, regardless of changes in blood vessel function or inflammation markers.
Giving vitamin D supplements to overweight or obese children and teens does not change their body mass index, blood sugar, insulin levels, or cholesterol levels.
In overweight and obese children and adolescents, vitamin D2 lowers HOMA-IR by 0.51 units more than vitamin D3.
In overweight and obese children and adolescents, taking vitamin D supplements lowers HDL cholesterol by 2.16 mg/dL.
Giving vitamin D supplements to overweight and obese children and adolescents does not change their insulin sensitivity, based on current evidence from controlled trials.
Current scientific evidence on whether vitamin D supplements affect heart and metabolic health in overweight and obese children and adolescents is considered low to moderate in reliability because the existing studies are small, inconsistent, and have methodological flaws.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.