A review of vitamin D fortification: implications for nutrition programming in Southeast Asia.

Background. VitaminD is vital for bone healthand has important roles in nonskeletal health and organ function. Most vitaminD is generated in the body by exposure to sunlight, with limited amounts added by the diet. Despite the presence of regular sunshine in Southeast Asia, vitaminD deficiency or insufficiency is being found there more commonly, primarily due to reduction of sunlight exposure as a result of lifestyle changes. Some of these lifestyle changes are unlikely to be reversed, and foods naturally containing vitaminD are not widely consumed, so fortificationof foods with vitaminD may raise vitaminD status. Methods. The literature database was searched for studies of vitaminD fortification, and we estimated potential vitaminD intakes from fortified vegetable oil. Results. Almost all of the studies showed that circulating vitaminD (25-hydroxyvitamin D [(25OHD]) increased in a dose-dependent manner with increased intake of vitaminD–fortified foods. However, in a number of studies the additional intake was insufficient to increase vitaminD levels to 50 nmol/L. Vegetable oilfortified with vitaminD at a level of 10 µg/100 g could provide 3.9% to 21% of the Institute of Medicine Estimated Average Requirement (EAR) of vitaminD for adults in Southeast Asia. Conclusions. Fortificationof widely consumed foods, such as edible oil, with vitaminD could contribute to improved vitaminD status in Southeast Asian countries. Intake modeling studies should be conducted to calculate the resulting additional intakes, and fortificationof additional foods should be considered. More nationally representative studies of vitaminD status in the region are urgently needed.