Tehran University of Medical Sciences Journal of Nutritional Sciences and Dietetics 5 3-4 2021 01 16 287 287 EN Amirhossein Yarparvar University of Vienna 2019 10 12 Background: Deficiency of Vitamin D, an anti-inflammatory micronutrient with some favorable effects on lipid profiles, has been found to be highly prevalent in adolescents. We aimed to investigate the effect of a high-dose vitamin D supplementation on the lipid and inflammatory profiles of healthy adolescent boys. Methods: In this randomized double-blind placebo-controlled trial, sixty healthy adolescent boys (age 17 yr) were recruited from one high school in Tehran, Iran and randomly assigned to two groups. The supplement group received vitamin D pearls at a dose of 50,000 IU monthly for 6 months and the other group was given placebo pearls for the same duration. Before and after the treatment, the serum levels of 25-hydroxy vitamin D (25(OH) D), parathyroid hormone (PTH), retinol, lead (Pb), the lipid profile and inflammatory biomarkers were measured and compared. Results: Between groups statistical analysis showed that a high dose (50,000 IU/month) vitamin D significantly increased and decreased serum levels of vitaamin D and PTH, respectively (P < 0.05). No significant change was observed in serum levels of retinol and Pb. Between-group analysis revealed that the serum levels of TG and HDL decreased and increased, respectively (P < 0.05). Both the within- and between-group analysis showed that serum tumor necrosis factor receptor 2 (TNFR2) concentration declined while serum interleukin-10 (IL-10) increased in response to vitamin D supplementation (P < 0.05). Conclusion: A high dose (50,000 IU/month) Vitamin D supplement seems to have some positive impact on serum vitamin D, lipid profile and inflammatory biomarkers in healthy adolescent boys. https://jnsd.tums.ac.ir/index.php/jnsd/article/view/287