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Background: Cystic fibrosis (CF) is a genetically disease with different respiratory and gastrointestinal organ involvement. Because of gastrointestinal tract involvement, patients have mal-absorption for vitamins and mineral elements for example vitamin A, D, E and trace elements such as Selenium (Se), Zinc (Zn) and Copper (Cu) have low serum level in CF patients in different studies. The goal of this study is to define relation between serum level of this elements and severity of respiratory and gastrointestinal tract involvement in these patients.
Materials and methods: This cross sectional study performed on 39 cystic fibrosis patients admitted in pediatric ward of Masih Daneshvari hospital, Tehran, Iran. Serum levels of Vitamin A, D and E, Selenium, Zinc and Copper deficiency were studied.
 Results: Serum level of Vitamin A and D were lower than normal values. Also, 3 cases (7.68%) had serum level of Zinc lower than normal values.
Conclusion: CF patients are susceptible to have deficiencies of fat soluble vitamins and trace elements such as Selenium and Zinc because of mal-absorption. It seems that a perfect diet and nutritional components are helpful in prevention of these problems.
Keywords: Cystic fibrosis, Zinc, Copper, Selenium, Vitamin.