Using food fortification to improve vitamin D bioaccessibility and intakes

Abstract

Vitamin D intakes and status are low in many countries due to seasonal UVB exposure variation and the fact that few foods are naturally vitamin D rich. Data modelling studies show that vitamin D intakes increase with food fortification, and countries with mandatory fortification policies have higher vitamin D intakes and status compared to countries without. While many foods can be vitamin D fortified, vitamin D bioavailability differs depending on fortification methods, food structure and composition. Randomised controlled trials (RCT) report that vitamin D2 bioavailability varies between foods, whereas vitamin D3 is bioavailable from many foods. In vitro studies suggest that altering the lipid composition of fortified foods increases vitamin D3 absorption. Olive oil increased vitamin D3 absorption during in vitro digestion compared to other dietary oils. Additionally, when vitamin D3 was incorporated into micelles formed from in vitro digestion of olive oil, more vitamin D3 was absorbed compared to other dietary oils. However, in a human postprandial study, a preformed vitamin D3 micelle dairy drink did not increase vitamin D3 absorption, and a vitamin D3 olive dairy drink increased vitamin D3 absorption in vitamin D insufficient participants only. Action is urgently needed to improve vitamin D intakes and status worldwide. Food fortification improves vitamin D intakes; however, fortification strategies unique to each country are needed. This review will synthesise the literature describing data modelling and intervention trials that assess the safety and efficacy of vitamin D fortification strategies, and those manipulating food composition to alter vitamin D bioavailability from fortified foods. Additionally, RCT examining the impact of vitamin D fortification strategies on vitamin D intakes and status over time are reviewed.

Vitamin D status in active duty Navy military personnel: a systematic review

“…In line with this trend, the number of US military active duty SM prescribed oral supplements solely of vitamin D increased 55-fold (from 0.3 to 18.3 SM/1000 SM) between 2005 and 2013; over this 9-year period 14 283 Navy active duty SM were prescribed oral supplements solely of vitamin D 7 8. This fact draws attention to the value of vitamin D food fortification that should also be considered in the context of the Navy 9 10…”

Addressing vitamin D deficiency through nutritional strategies

“…Fortified foods, such as dairy products, fruit juice, and breakfast cereals can contribute to vitamin D status [21]. Traditional fortification entails incorporating a specialized blend of vitamin D, which could be in the form of an oil blend, dried dairy powder, or dried grains, into foods in carefully measured quantities [20]. Table 2 lists some foods alongside their vitamin D content per serving, using data provided by the NIH.…”

“…Some researchers argue for global implementation of vitamin D fortification policies, advocating for randomized controlled trials to guide effective policy design [19][20]. An overview of clinical studies on fortified vitamin D foods in the last ten years is shown in Table 3.…”

Effects of Isoflavonoid and Vitamin D Synergism on Bone Mineral Density—A Systematic and Critical Review

“…The rich dietary sources of vitamin D involve only certain fish types, mushrooms and fish liver oils; whereas a lower vitamin D content can be found in cheese, beef liver, eggs or chocolate [54]. In some countries, vitamin D food fortification programs are implemented with an observed improvement in 25(OH)D concentrations at a population level [55]. In order to achieve the most biologically active vitamin D metabolite-calcitriol (1α,25(OH)2D)-two enzymatic hydroxylation reactions are required: 25-hydroxylation (in the liver) and hydroxylation at position 1α (mainly in the kidneys).…”