The Effect of Educational Intervention Based on The Health Belief Model on using vitamin D Supplements Among Female High School Students in Mashhad

Background: Teenage girls are one of the high-risk groups for vitamin D deficiency. This study aimed to determine the effect of an educational intervention based on the health belief model on the use of vitamin D supplements among female high school students.   Methods: In this quasi-experimental study, 140 girl high school students (n=70 in each group) in Mashhad in the academic year 2015-2016 participated. The research tools included a demographic information questionnaire and a researcher made questionnaire of knowledge and the HBM constructs regarding the use of vitamin D supplements. After collecting pre-test data, the educational intervention was implemented for students in the test group and the post-tests were carried out immediately and three months after intervention. Data were analyzed using SPSS software v19 and applying appropriate statistical tests.   Results: Before the study there were no significant differences in all variables and constructs. But after the educational intervntion a significant difference was reported between the intervntion and control group concerning knowledge, perceived susceptibility, perceived severity, perceived benefit (P<0.001), perceived barrier (P=0.001), self-efficacy and use of vitamin D supplements (P<0.001). The results in the test group showed that the average scores of knowledge, all health belief models’ components and use of vitamin D supplements before, immediately and three months after the intervention were significantly different (P<0.001).   Conclusion: Health education programs based on the health belief model can be useful in promoting health awareness and use of vitamin D supplements.