BACKGROUND: Previous studies have reported a high frequency of vitamin D deficiency (VDD) among different age groups in Iran. AIMS: In this study, the current coverage, status of vitamin D supplement taking, and program efficacy have been evaluated by the Office of Nutrition Department Society in Iran since 2014. METHODS: This study was conducted in collaboration with the International UNESCO center for Health-Related Basic Sciences and Human Nutrition and the Office of Nutrition Department Society. Sixty three medical universities were included in the current study to calculate the availability, accessibility and acceptability coverages. Furthermore, 3 medical universities including Mashhad (MUMS), Qom (QUMS) and Zahedan (ZAUMS) University of Medical Sciences were selected based on the results of the National Integrated Micronutrient Survey 2012 (NIMS-II study), in order to assess the status of vitamin D supplement intake in all age ranges. RESULTS: Quantitative analysis showed that availability coverage was 74.96% and 77.56% and accessibility was 80.70% and 83.26% in elderly and middle-aged subjects, respectively in 2018. The acceptability was approximately 43.7% and 43.9% among elderly and middle-aged participants, respectively. The availability and acceptability coverage was 80.99% and 85.0% among students in high schools. The mean vitamin D supplement uptake frequency was 27.0% (n = 387); 20.7% and 29.2% in rural and urban area, respectively (P = 0.001). The results showed that there was no significant difference in serum vitamin D levels between urban (20.41 ± 6.43 ng/ml) and rural areas, (P = 0.887). There was no significant difference in the serum vitamin D concentrations between men and women (P = 0.461). CONCLUSIONS: The frequency of taking vitamin D supplements was 27.0% in Iran in 2018. The frequency of taking of vitamin D supplements among vitamin D deficient group (serum vitamin D levels <19.99 ng/ml) was 43.6%. Lack of knowledge was the most important reason for not taking vitamin D supplement. Moreover, the serum vitamin D levels have increased in subjects aged 18-30 years old after the implementation of the vitamin D supplementary program.