Objective: The aim of this study is to determine the best foods for potential Vitamin D food fortification and to model the efficacy and safety of different food fortification scenarios in adults aged 50+ years in Ireland. Research Methods & Procedures: National Adult Nutrition Survey Vitamin D data for participants aged 50+ years was updated. Vitamin D from foods with natural and added Vitamin D was estimated and daily Vitamin D intake patterns were examined. Data modelling was used to estimate the impact of target food fortification scenarios. Results: Almost two thirds of the mean daily Vitamin D intake of adults aged 50+ years (7±۷µg) comes from foods with added Vitamin D. Milks and breads are the most frequently consumed foods across all meals and were subsequently targeted for the data modelling exercise. Results from the data modelling show that Vitamin D intakes increased between 9- 17µg daily, depending on the fortification scenario. Fortifying milk or bread resulted in ~30% or ~55% of individuals meeting the RDA; however fortifying both simultaneously resulted in ~70% meeting the RDA. Conclusion(s): Currently the majority of older Irish adults are not meeting dietary recommendations for Vitamin D. Fortification of commonly consumed foods such as milk and bread could improve daily intakes such that ~70% of the cohort would meet the minimum recommendation. Future research should examine the efficacy of different food fortification scenarios to improve Vitamin D intakes for older Irish adults.

Introduction

Vitamin D is a fat soluble nutrient essential for calcium homeostasis (1). Vitamin D status is measured by the metabolite 25-hydroxy-Vitamin D (25(OH)D) and the Institute of Medicine (IOM) define 25(OH)D concentrations of <50nmol/L as insufficient and <37.5nmol/L as deficient (2). Vitamin D can be synthesised in the skin on exposure to sunlight; however, synthesis is limited at northerly latitudes due to low ultraviolet B (UVB) exposure. For this reason, a large proportion of people in northern European countries, including Ireland, have insufficient circulating 25(OH)D (3-6). Vitamin D can also be consumed in foods, and dietary sources are critical in certain populations where skin synthesis does not meet physiological needs (4-6). However, dietary Vitamin D is also a concern as there are only a few foods that contain natural Vitamin D such as oily fish, egg yolk and meat. Other foods like milk and breakfast cereals that contain little or no natural Vitamin D can be fortified to improve intakes. Evidence from research suggests that fortified foods are important dietary sources of Vitamin D and therefore contribute to improved Vitamin D-related health outcomes (7).