The data that support the findings of this study are available on request from the corresponding author (SJ). The data are not publicly available due to it was funded by the Southern Thailand Institute of Research and Development and some data contained information that could compromise the privacy of research participants.
Steps to reproduce
All statistical analyses were performed using the R program (R Foundation, Austria available from http://www.r-project.org/foundation/main.html). The demographic data were expressed in number and percentages (categorical variables) or mean standard deviation and ranges (continuous variables). The vitamin D intake was calculated as mean, standard deviation. The numbers and proportions of the participants with low and adequate serum 25-OHD concentrations were compared using the chi-square test and biochemical levels were compared by t-test. Pearson correlation was used to identify the relationship between serum level of 25-OHD and other biochemical variables.