152 Asia Pac J Clin Nutr 2007;16 (1):152-157 Original Article Sub clinical vitamin A deficiency and anemia among Vietnamese children less than five years of age Nguyen Cong Khan MD, PhD 1,2 , Nguyen Xuan Ninh MD, PhD 1 , Nguyen Van Nhien MD 1 , Ha Huy Khoi PhD, DSc 1 , Clive E West PhD 3,4 (deceased) and Joseph GAJ Hautvast MD, PhD 3 1 National Institute of Nutrition, Hanoi, Vietnam 2 Division of Nutrition, Hanoi School of Public Health, Vietnam 3 Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands 4 Department of Gastroenterology, University Medical Center, Nijmegen, The Netherlands The objective of the study was to assess the prevalence of sub clinical vitamin A deficiency and anemia in Vietnamese children. For this, a cross-sectional survey was conducted in 40 villages (clus- ters) of four ecological regions in Vietnam during Apr-May 2001. In total 1657 children less than 5 years old were included by a cluster random sampling method. The prevalence of sub clinical vita- min A deficiency (serum retinol <0.70 μmol/L) was 12.0% and the prevalence of anemia (hemoglo- bin <110g/L) was 28.4 %. In the children under 6 months the prevalence of sub clinical vitamin A deficiency was 35.1 % whereas the prevalence of anemia in this group was as high as 61.7%. The prevalence of children with both sub clinical vitamin A deficiency and anemia was 6.1%. Sub clini- cal vitamin A deficiency and anemia prevalence differed significantly across the regions, with high- est prevalence in the Northern Mountainous areas for vitamin A deficiency and in the Northern Mountainous area and Mekong River Delta for anemia. It is concluded that sub clinical vitamin A deficiency and anemia are still important public health problems in Vietnam. Sustainable strategies for combating vitamin A deficiency and nutritional anemia are needed and should concentrate on target groups, especially infants and malnourished children in high risk regions. Key Words: vitamin A deficiency, anemia, children urban, rural prevalence, Vietnam Introduction Vitamin A deficiency and iron deficiency anemia can have important health consequences for preschool children. These include growth failure, depressed immune responses, higher risk of xerophthalmia and blindness and increased morbidity and mortality. 1,2 Globally, it is estimated that about 127 million preschool children under 5 years of age are vitamin A deficient, of whom 4.4 million have xe- rophthalmia. 3 Iron deficiency, not only the main cause of anemia in Vietnam, but also a major problem among pre- school children worldwide, has been associated with re- tarded psychomotor development and growth retardation. 4,5 During the 1980’s vitamin A deficiency and xerophthal- mia in children younger than 5 years was a serious nutri- tional problem in Vietnam. 6,7 A country-wide survey done in 1994 showed that the prevalence of clinical forms of vitamin A deficiency were lower than the threshold of being a public health problem set by WHO (7, 8). A small sample survey reported that the prevalence of sub-clinical vitamin A deficiency (serum retinol <0.7 μmol/L) ranged from 14.7% in 1995 to 12% in 1997. 6 There is lack of information on the prevalence of sub-clinical vitamin A deficiency in the various ecological regions in Vietnam and it can be assumed that the prevalence varies with age, poverty and prevalence of malnutrition. There is also lack of data on the prevalence of anemia in children in Vietnam. A survey on anemia and nutritional risk factors conducted in 1995 showed a high prevalence of anemia in preschool children and in adult women. 9 Therefore, the aims of the present study were to assess the prevalence of sub-clinical Vitamin A deficiency and anemia among children less than five years of age in 4 different ecological region of Vietnam including Northern Mountainous, Red River Delta, South Central Coast and Mekong River Delta. Subjects and methods A cross-sectional survey was conducted in 4 out of the in total 8 ecological regions of Vietnam, including Northern Mountainous, Red River Delta, South Central Coast and Mekong River Delta. Corresponding Author: Dr Nguyen Cong Khan, National Insti- tute of Nutrition, 48B Tang Bat Ho, Hanoi, Vietnam. Tel: + 84 4 9716058/ + 84 4 9717090; Fax: + 84 4 9717885 Email: nckhan@hn.vnn.vn Manuscript received 8 March 2006. Accepted 11 May 2006.