Vitamin A status and recurrent respiratory infection among Chinese children: A nationally representative survey.

BACKGROUND AND OBJECTIVES: Vitamin A is involved in immune function, vision, reproduction, and cell differentiation and is essential for child growth. Vitamin A deficiency (VAD) contributes significantly to mortality and morbidity in developing countries. This study assessed the current vitamin A status in Chinese children. METHODS AND STUDY DESIGN: A cross-sectional survey was conducted in 26 provinces in China between 2015 and 2018, and 277,064 children aged 0-14 years were enrolled. Data on sociodemographic factors and dietary supplements were obtained through interviews with their parents. Serum vitamin A concentrations were measured using HPLC. To reduce the sampling error, a weighted distribution was produced to estimate the distribution of serum vitamin A concentration in Chinese children. A new method was used calculate the CI. RESULTS: The results revealed that 10.4% (23.9 million) (95% CI: 10.1%-10.8%) of Chinese children aged 0-14 years were at risk of suffering from subclinical VAD (SVAD) (<0.2 mg/L). Sick children, especially those with recurrent respiratory infections (21.3%, 95% CI: 20.5%-22.2%), were vulnerable to SVAD. A high prevalence of SVAD was observed in western and northeastern areas in China. Serum vitamin A concentrations in ethnic minority groups were significantly lower than those in Han Chinese children (p<0.01). CONCLUSIONS: VAD is still a moderate public health problem in Chinese children, especially in those with respiratory symptoms. Regular consumption of vitamin A-rich foods should be promoted through nutrition education for parents.