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

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.