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

BACKGROUND: Vitamin D is vital for bone health and has important roles in nonskeletal health and organ function. Most vitamin D 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, vitamin D 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 vitamin D are not widely consumed, so fortification of foods with vitamin D may raise vitamin D status.

METHODS: The literature database was searched for studies of vitamin D fortification, and we estimated potential vitamin D intakes from fortified vegetable oil.

RESULTS: Almost all of the studies showed that circulating vitamin D (25-hydroxyvitamin D [(25OHD]) increased in a dose-dependent manner with increased intake of vitamin D-fortified foods. However, in a number of studies the additional intake was insufficient to increase vitamin D levels to 50 nmol/L. Vegetable oil fortified with vitamin D at a level of 10 microg/100 g could provide 3.9% to 21% of the Institute of Medicine Estimated Average Requirement (EAR) of vitamin D for adults in Southeast Asia.

CONCLUSIONS: Fortification of widely consumed foods, such as edible oil, with vitamin D could contribute to improved vitamin D status in Southeast Asian countries. Intake modeling studies should be conducted to calculate the resulting additional intakes, and fortification of additional foods should be considered. More nationally representative studies of vitamin D status in the region are urgently needed.