Study on urine metabolomics of left-behind children with vitamin D deficiency under 1 year old in Zunyi area based on nuclear magnetic resonance

Objective To explore the characteristic changes in urinary metabolites in left-behind children with vitamin D deficiency under 1 year old in Zunyi area by metabolomic nuclear magnetic resonance (NMR) in order to provide new biomarkers for early diagnosis of vitamin D deficiency. Methods From January to August 2018, blood tests and urine collection were carried out on the left-behind children under 1 year old in Fenggang county, Bozhou district and Zheng′an county under Zunyi city by stratified sampling.Forty children diagnosed as a vitamin D deficiency were selected as a vitamin D deficiency group, and 40 children with normal urine test were selected as a healthy control group.For urine sampling, SIMCA-P+ software was applied to analyze the integral value of hydrogen spectrogram by principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) was used to distinguish the difference in urine metabolites between two groups of the left-behind children.Orthogonal partial least squares discriminant analysis (OPLS-DA) was used to screen different metabolites. Results The serum level of 25-hydroxy vitamin D[25-(OH)D][(32.0±3.6) nmol/L ] in the healthy control group was higher than that in the vitamin D deficiency group[(15.8±2.3) nmol/L], and the difference was statistically significant (P 0.602, all P 0.602, all P<0.05, df=39). Conclusions The left-behind children under 1 year old with vitamin D deficiency in Zunyi region are mainly characterized by disorder in energy metabolism, lipid metabolism, amino acid metabolism and intestinal microbial meta-bolism disorders, and their differential metabolites have potential application value in early diagnosis and pathogenesis of vitamin D deficiency. Key words: Vitamin D deficiency; Nuclear magnetic resonance; Metabolomics; Differential metabolites