Estimation of Vitamin D Intake Based on a Scenario for Fortification of Dairy Products with Vitamin D in a Tehranian Population, Iran

Abstract

Objective: The aim of this study was to evaluate possible effects of food fortification practices on vitamin D intake in adults.

Design and setting: This was designed as a cross-sectional, population-based study.

Subjects: We investigated vitamin D intake in a population-based sample of 5224 adults, using a validated food frequency questionnaire. A theoretical model was conducted to evaluate the hypothetical effects of dairy product fortification.

Results: Dairy had the highest mean of vitamin D intake among food groups. If all types of milk were fortified by vitamin D (42 IU/100 grams of milk), the mean intake of vitamin D would reach 132 ± 148 (92(180)) IU/day. If both milk and yogurt were fortified to 42 IU/100 g and 89 IU/100 g, respectively, the average mean vitamin D intake from foods in this population would increase from 84 ± 88 IU/day to 308 ± 240 IU/day. As the fortification level increased, the proportions of young people with more than the recommended daily allowance (RDA) of vitamin D increased from 1.1% to 77.4% in men and from 1.4% to 80% in women, but none of them achieved the tolerable upper intake level (UL) of vitamin D.

Conclusion: The proposed fortification scenario would provide enough vitamin D intakes by RDA in a population aged between 18 and 50 years (about 80% of the population), with none of them achieving ULs.

Key words:

• vitamin D
• fortification
• adults
• Iran

ACKNOWLEDGMENTS

The authors wish to acknowledge Ms. Niloofar Shiva for critical editing of English grammar and syntax of the manuscript. The authors have no conflicts of interest to report regarding this study. There is no funding source.

AUTHORS' CONTRIBUTIONS

Hanieh Ejtahed performed most of the statistical analyses and wrote the preliminary manuscript. Dr. S. Shab-Bidar designed and supervised the study, analyzed data, wrote the finalized manuscript, and had primary responsibility for final content. Dr. F. Hosseinpanah, Dr. P. Mirmiran, and Dr. F. Azizi helped intellectually in finalizing the study manuscript. All authors have read and approved the final manuscript.