Objective: To study the relationship between dietary vitamin A intake and plasma vitamin A concentration, and establish the theoretical basis for dietary intake predicting vitamin A nutritional status.
Methods: By using cluster sampling, 492 children aged 2-7 years in kindergartens in Banan district of Chongqing were selected. A cross-sectional nutrition and health survey was conducted, including the clinical examination, anthropometry, laboratory test and dietary survey.
Results: Among the children surveyed, 229 were boys, and 263 girls, the mean age was (4.54 ± 0.87) years, height (107.50 ± 7.20) cm, and weight (18.42 ± 3.41) kg, the mean value of plasma vitamin A was (1.04 ± 0.30) μmol/L. The prevalence of marginal vitamin A deficiency (MVAD) was 43.5%. No cases of severe clinical vitamin A deficiency were found (plasma vitamin A ≤ 0.35 μmol/L). Clinical examination found no conjunctiva, corneaor skin abnormalities, and no Bitot's spots. Prevalence of the last two weeks colds were 27.4% (135/492), no diarrhea and other gastrointestinal or digestive diseases were found. The proportion of insufficient dietary vitamin A intake (<600 μg RE/d) was as high as 50.0%. By using correlation analysis, plasma retinol concentrations were related to dietary vitamin A intake (r=0.162, P<0.001), and to dietary energy intake (r=0.107, P=0.017). After adjustment for the effects of other non-dietary factors on vitamin A deficiency, the multivariate logistic regression showed that vitamin A-rich foods of liver intake=0 g/d (OR=1.95, 95% CI: 1.05-3.61, P=0.034), vitamin A-rich fruits intake=0 g/d (OR=1.55, 95% CI: 1.03-2.33, P=0.034), vitamin A-rich vegetables intake<200 g/d (OR=3.47, 95% CI: 1.37-8.75, P=0.009) were important risk factors of vitamin A deficiency. But we had not found the correlation between the intake of meat, eggs and milk and vitamin A deficiency.
Conclusion: Dietary factors may be the major risk factor of vitamin A deficiency in the three kindergartens. The dietary vitamin A intakes are significantly related to plasma retinol concentrations, and the vitamin A-rich foods intakes can predict the body's vitamin A nutritional status.