Estimation and Validation of Dietary Nitrate and Nitrite Intake in Iranian Population

Abstract

Background: The aim of this study was calibration of a nitrate (NO₃)/nitrite (NO₂) database for estimated its dietary intakes.

Methods: Overall, 250 healthy Tehranian adults were assessed in 2015 for dietary intakes of NO₃ and NO₂ and its serum and urine concentration. Food composition values for NO₃ and NO₂ were derived from a recent survey conducted on frequently consumed food items among Iranians. The correlation of dietary intakes of NO₃/NO₂ and its urinary and serum values was evaluated.

Results: Mean (±SD) intakes of dietary NO₃ and NO₂ were 505±160 and 7.7±2.2 mg/d, respectively. The correlation coefficient of intake and urinary NO₃ was 0.83 (95% CI=0.56-0.91) and 0.57 (95% CI=0.49-0.67) in men and women, respectively. A moderate agreement was also observed between NO₂ intake and its urinary levels (r=0.27, 95% CI=0.13-0.37, and 0.29, 95% CI=0.17-0.41, in men and women, respectively).

Conclusion: Using a national database of NO₃ and NO₂ content of food items along with a valid food frequency questionnaire could provide a valid estimation of dietary intakes of NO₃ in the target population.