The South East Asian Nutrition Surveys (SEANUTS) were conducted in 2010/2011 in Indonesia, Malaysia, Thailand and Vietnam in country representative samples totalling 16,744 children aged 0.5 to 12 years. Information on socio-demographic and behavioural variables was collected using questionnaires and anthropometric variables were measured. In a sub-sample of 2016 children, serum 25-hydroxy-vitamin D (25(OH)D) was determined. Data were analysed using SPSS complex sample with weight factors to report population representative data. Children were categorized as deficient (<25 nmol/L), insufficient (<50 nmol/L), inadequate (<75 nmol/L) or desirable (>=75 nmol/L). In Malaysia and Thailand, urban children had lower 25(OH)D than rural children. In all countries, except Vietnam, boys had higher 25(OH)D levels and older children had lower 25(OH)D. Regional differences after correcting for age, sex and area of residence were seen in all countries. In Thailand and Malaysia, 25(OH)D status was associated with religion. The percentage of children with adequate 25(OH)D (>=75 nmol/L) ranged from as low as 5% (Indonesia) to 20% (Vietnam). Vitamin D insufficiency (<50 nmol/L) was noted in 40 to 50% of children in all countries. Logistic regression showed that girls, urban area, region within the country and religion significantly increased the odds for being vitamin D insufficient. The high prevalence of vitamin D insufficiency in the (sub) tropical SEANUTS countries suggests a need for tailored approach to successfully combat this problem. Promoting active outdoor livestyle with safe sunlight exposure along with food-based strategies to improve vitamin D intake can be feasible options.
Nutrition is a well-known factor in the growth, health and development of children. It is also acknowledged that worldwide many people have dietary imbalances resulting in over- or undernutrition. In 2009, the multinational food company FrieslandCampina initiated the South East Asian Nutrition Survey (SEANUTS), a combination of surveys carried out in Indonesia, Malaysia, Thailand and Vietnam, to get a better insight into these imbalances. The present study describes the general study design and methodology, as well as some problems and pitfalls encountered. In each of these countries, participants in the age range of 0·5-12 years were recruited according to a multistage cluster randomised or stratified random sampling methodology. Field teams took care of recruitment and data collection. For the health status of children, growth and body composition, physical activity, bone density, and development and cognition were measured. For nutrition, food intake and food habits were assessed by questionnaires, whereas in subpopulations blood and urine samples were collected to measure the biochemical status parameters of Fe, vitamins A and D, and DHA. In Thailand, the researchers additionally studied the lipid profile in blood, whereas in Indonesia iodine excretion in urine was analysed. Biochemical data were analysed in certified laboratories. Study protocols and methodology were aligned where practically possible. In December 2011, data collection was finalised. In total, 16,744 children participated in the present study. Information that will be very relevant for formulating nutritional health policies, as well as for designing innovative food and nutrition research and development programmes, has become available.