The phenomenon of micronutrient deficiency among children in China: a systematic review of the literature.

OBJECTIVE: The present study aimed to review the literature on micronutrient deficiency and other factors influencing a deficiency status among children living in China. DESIGN: A systematic review was performed to analyse the literature. SETTING: Studies were identified through a search of PubMed and secondary references. SUBJECTS: Children living in China aged less than 18 years. RESULTS: Sixty-one articles were included. The prevalence of vitamin A deficiency decreased to approximately 10 % in 1995-2009. It increased with age but no significant difference was found between genders. The prevalence of thiamin and vitamin B12 deficiency was 10·5 % in Yunnan and 4·5 % in Chongqing provinces, respectively. Higher vitamin D deficiency rates were seen in spring and winter. The incidence of bleeding due to vitamin K deficiency was 3·3 % in 1998-2001 and more prevalent in rural areas. Both iodine deficiency and excess iodine intake were observed. Goitre rates were reported in Tibet, Jiangxi, Gansu and Hong Kong (3·5-46 %). Anaemia rates ranged from 20 % to 40 % in 2007-2011. High Se deficiency rates were found in Tibet, Shaanxi and Jiangsu. High Zn deficiency rates were also found (50-70 %) in 1995-2006. Few studies reported Ca deficiency rates (19·6-34·3 %). The degrees of deficiency for vitamin A, vitamin B12, Fe and Zn were more substantial in rural areas compared with urban areas. CONCLUSIONS: The prevalence of micronutrient deficiency rates varied. Socio-economic status, environmental factors and the Chinese diet may influence micronutrient deficiency. Public health policies should consider implementing programmes of supplementation, food fortification and nutrition education to address these deficiencies among Chinese children.