Prevalence of subclinical vitamin A deficiency and its affecting factors in 8 669 children of China

Abstract

Objective: The survey will reveal current status of subclinical vitamin A deficiency (SVAD) and explore its affecting factors in children of China.

Methods: Totally 8 669 children aged under 6 years were randomly selected from 14 provinces for clinical examination, health and dietary questionnaire and serum level of vitamin A measurement with fluorescence method. The cut-off value for SVAD was defined as </= 0.70 micro mol/L.

Results: Prevalence of SVAD was 11.7% and that of suspected SVAD 39.2% in all subjects, which decreased with the increase of gross domestic product, average annual family income, mother's schooling and children's age. Prevalence of SVAD and suspected SVAD higher in rural areas (15.0%) than in urban areas (5.2%), and higher in children with a minority mother (22.6%) than in those with a Han nationality mother (8.7%). Prevalence of SVAD and suspected SVAD was higher in children whose blood samples were collected within one week in-taking vitamin A-rich food (12.6%-22.6%) than those in-taking vitamin A daily (4.1%-10.0%), and higher in children suffering from respiratory infection, fever and diarrhea two weeks before their blood collection (15.2%-20.3%) than in those without those diseases (10.1%-11.1%). Logistic regression analysis showed that poor family economic status, living in rural areas, children with a minority mother, younger age, no-dairy milk products intake, and respiratory infection and fever all were risk factors for SVAD.

Conclusions: More than half of children under six years old in China (50.9%) had vitamin A nutrition problem. Varied factors played roles to different extent in SVAD in children.