P812 - THE EFFECTS OF VITAMIN D-FORTIFIED MILK ON NUTRITIONAL STATUS OF JUNIOR HIGH SCHOOL STUDENTS IN RURAL AREAS OF CHINA

P812

THE EFFECTS OF VITAMIN D-FORTIFIED MILK ON NUTRITIONAL STATUS OF JUNIOR HIGH SCHOOL STUDENTS IN RURAL AREAS OF CHINA

Q. Zhuo^1,*, Z. Yang¹, L. Shi¹, J. Huo¹, T. Liu¹, C. Han¹

¹National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, Beijing, China

Rationale: Vitamin D deficiency is a major public health issue，especially among rural adolescents in China. This study aimed to explore the effects of vitamin D-fortified milk supplementation on improving the nutritional status of rural boarding school students.

Methods: A 12-month randomized controlled trial was conducted among 141 rural boarding students (aged 13-15 years) in Henan, China. Participants were randomised into the intervention group receiving 5 µg vitamin D-fortified milk daily or the control group receiving ordinary milk. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA). Serum 25(OH)D was quantified by LC-MS/MS, serum calcium was analyzed with automated biochemistry analyzer, and parathyroid hormone (PTH), bone turnover markers including osteocalcin (OST), procollagen type I N-terminal propeptide (PINP), and C-terminal telopeptide of type I collagen (CTX) were measured by electrochemiluminescence immunoassay. Data were analyzed using t-test, Wilcoxon signed-rank test and difference-in-differences analysis.

Results: The results revealed temporal variations in physical development across groups (P<0.05), with consistent longitudinal trajectories. A significant elevation in serum 25(OH)D was observed in the intervention group (P<0.0001) compared with a marked reduction in the control group. (P<0.05). Serum 25(OH)D levels increased by 5.57 ng/mL in the intervention group than in the control group (P<0.0001). Significant increases in BMD were observed in both groups (P<0.05). Daily supplementation with vitamin D-fortified milk markedly reduced PTH levels and increased serum calcium (P<0.05). Concurrently, bone turnover markers decreased significantly (P<0.05).

Conclusion: This study indicates that nutritional status of rural adolescents could be effectively improved by vitamin D-fortified milk.

Disclosure of Interest: None declared