title: The phenomenon of micronutrient deficiency among children in China: a systematic review of the literature.
abstract: OBJECTIVE
  The present study aimed to review the literature on micronutrient deficiency and other factors influencing a deficiency status among children living in China.
  
  
  METHODS
  A systematic review was performed to analyse the literature.
  
  
  METHODS
  Studies were identified through a search of PubMed and secondary references.
  
  
  METHODS
  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.
authors.affiliation: 1Centre for Safe Medication Practice and Research,Department of Pharmacology and Pharmacy,Li Ka Shing Faculty of Medicine,The University of Hong Kong,2/F Laboratory Block,21 Sassoon Road,Hong Kong Special Administrative Region,People's Republic of China.
authors.forename: Angel Y S
authors.initials: AY
authors.lastname: Wong
authors.affiliation: 1Centre for Safe Medication Practice and Research,Department of Pharmacology and Pharmacy,Li Ka Shing Faculty of Medicine,The University of Hong Kong,2/F Laboratory Block,21 Sassoon Road,Hong Kong Special Administrative Region,People's Republic of China.
authors.forename: Esther W
authors.initials: EW
authors.lastname: Chan
authors.affiliation: 1Centre for Safe Medication Practice and Research,Department of Pharmacology and Pharmacy,Li Ka Shing Faculty of Medicine,The University of Hong Kong,2/F Laboratory Block,21 Sassoon Road,Hong Kong Special Administrative Region,People's Republic of China.
authors.forename: Celine S L
authors.initials: CS
authors.lastname: Chui
authors.affiliation: 2General and Adolescent Paediatric Unit,UCL Institute of Child Health,University College London,London,UK.
authors.forename: Alastair G
authors.initials: AG
authors.lastname: Sutcliffe
authors.affiliation: 1Centre for Safe Medication Practice and Research,Department of Pharmacology and Pharmacy,Li Ka Shing Faculty of Medicine,The University of Hong Kong,2/F Laboratory Block,21 Sassoon Road,Hong Kong Special Administrative Region,People's Republic of China.
authors.forename: Ian C K
authors.initials: IC
authors.lastname: Wong
mesh_terms: D000293:Adolescent; D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D004032:Diet; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007455:Iodine / Q000097:blood / Q000172:deficiency; D044342:Malnutrition / Q000097:blood / Q000453:epidemiology*; D018977:Micronutrients / Q000097:blood / Q000172:deficiency*; D009752:Nutritional Status; D015995:Prevalence; D011634:Public Health; D012424:Rural Population; D012621:Seasons; D012959:Socioeconomic Factors; D014802:Vitamin A Deficiency / Q000097:blood / Q000453:epidemiology*; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000453:epidemiology*; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*; D015032:Zinc / Q000097:blood / Q000172:deficiency
chemical_list: D018977:Micronutrients; D007455:Iodine; D015032:Zinc