Association Between Vitamin D Status and Undernutrition Indices in Children: A Systematic Review and Meta-Analysis of Observational Studies

Introduction: Undernutrition, defined as stunting, wasting, and underweight, still implicates millions of infants and children worldwide. Micronutrients have pivotal effects on growth rate. The outcomes of vitamin D deficiency on undernutrition indices have stayed controversial. The object of current study is to answer this question: is there any association between vitamin D status and undernutrition indices? Methods: The international databases were used for a systematic search to identify relevant observational studies in English up to January 2021. A random-effect model was applied to combine the results of included essays. Results: Among 3,400 citations, 7 observational studies (4 cohorts and 3 cross-sectional) were eligible to enter in meta-analysis. Analysis of the lowest 8,295 children indicated that low vs. high serum level of vitamin D is directly associated with a higher risk of wasting (Summary Risk Estimate: 1.30; 95% CI: 1.04, 1.62; I-2 = 0%). However, there is no significant association between vitamin status and risk of stunting (Summary Risk Estimate: 1.10; 95% CI: 0.72, 1.70; I-2 = 81.6%) and underweight (Summary Risk Estimate: 1.12; 95% CI: 0.81, 1.56; I-2 = 49.2%). Conclusion: When comparing low and high serum vitamin D concentration categories, there is an inverse link between vitamin D status and wasting, but no relationship with stunting as well as underweight. However, further prospective and trial studies are required to deepen our understanding of these associations.

Automated summary

This study found a direct association between low levels of vitamin D and an increased risk of wasting, but no significant relationship with stunting or underweight risks. Further prospective and trial studies are needed to deepen our understanding of these associations.