Survey on Knowledge and Attitudes on Vitamin D and SunlightExposure in an Urban Population in Vietnam

Background. Vitamin D deficiency has been shown to be a risk factor for various chronic diseases and mortality. It is not clear why vitamin D deficiency affects a large proportion of individuals living in tropical Asian countries. Objective. The present study sought to examine the knowledge, behavior and attitude of Vietnamese men and women toward vitamin D and sunlight exposure. Methodology. The study was designed as a cross-sectional survey of a population in Ho Chi Minh City, Vietnam. Study participants were randomly drawn from the general community, supermarkets and hospital visitors. Each participant was given a questionnaire relating to knowledge on vitamin D and behavior toward sunlight exposure. The questionnaire was previously tested for reliability and accuracy in 20 participants. Results. A total of 1,536 individuals aged 14 to 85 years participated in the study. Fifty three percent of participants did not like being exposed to sunlight. On the average, most reported approximately 14 hours per week under the sun. Majority (81%) reported that they had heard of vitamin D from newspapers (32%), friends (20%) or radio and television (13%). However, their knowledge about the source of vitamin D was inadequate: 37% thought that vitamin D comes from the sun, 28% from foodstuff and the sun, while 17% did not know the source of vitamin D. Analysis of the determinants of knowledge of vitamin D suggested that only educational level was a significant predictor of vitamin D knowledge. Conclusion. A negative attitude toward sunlight exposure and inadequacy of knowledge on vitamin D could adversely affect bone and general health in the community. The data also provides a basis for developing public health strategies for the prevention of vitamin D deficiency in the Vietnamese population.