Strategic food vehicles for vitamin D fortification and effects on vitamin D status: A systematic review and meta-analysis of randomised controlled trials

High reliance on fortified foods when optimizing diets of adolescents in Sweden for adequate vitamin D intake and climate sustainability

The global food system contributes roughly one-third of global greenhouse gas emissions (GHGEs) making shifts towards more sustainable food consumption an imperative. Such diets also need to factor in nutrient requirements and cultural acceptability. Our aim was to simulate dietary changes for adolescents in Sweden to achieve the recommended intake (RI) for vitamin D while factoring in additional nutrients, cultural acceptability and keeping the diet within planetary boundaries for climate change. A baseline diet was estimated from Sweden's national dietary survey Riksmaten Adolescents 2016-17 (n = 3099, ages 11-18 years), which provided food intake via two 24-hour recalls. Intake data were linked to the Swedish Food Agency's food composition database and GHGE estimates from the Research Institutes of Sweden's (RISE) Food Climate Database. Linear programming was used to optimize the baseline diet to meet the RI for vitamin D (10 µg/day), reduce GHGEs to ≤ 1.7 kg CO2-equivalents/person/day, and minimize dietary changes from baseline to factor in cultural acceptability. A second optimization included 25 additional nutrients requirements. Both optimized diets met their respective requirements reducing GHGEs by 54 % but relied heavily on milk and yoghurt (fortified by law), which provided > 60 % of vitamin D intake. Both diets also required major shifts toward plant-based foods and the second optimization demanded a five-fold greater change in diet from baseline compared to first optimization. Results suggest that adolescents in Sweden can achieve RIs for vitamin D and other nutrients while greatly reducing diet-related GHGEs, though cultural acceptability may be a challenge.

The potential impact of the extended vitamin D fortification policy during pregnancy varies by continent of origin - a population-representative Swedish cohort

PURPOSE

We aimed to explore the potential impact of Sweden's extended fortification policy, launched in 2018, on vitamin D intake during pregnancy, depending on continent of origin.

METHODS

The population-representative GraviD cohort was conducted within the antenatal care in 2013-2014 in Southwestern Sweden. Background data including country of origin were collected through questionnaires. In the third trimester, participants (N = 1761) answered a vitamin D questionnaire which included intakes of margarine, milk, and fermented milk. Reported vitamin D intake in 2013-2014 was compared to simulated vitamin D intake following the 2018 vitamin D fortification policy expansion.

RESULTS

Pre-expansion reported median intake of vitamin D from fortified foods differed by continent of origin (p < 0.001). Pre-expansion intake was highest among participants from Northern Europe (2.4 µg/day) compared to those from Continental Europe (2.0 µg/day, p = 0.002), Asia (1.6 µg/day, p < 0.001), and Africa (2.0 µg/day, p = 0.001). Post-expansion simulated median vitamin D intake from fortified foods was higher among participants from Northern Europe (6.3 µg/day) compared to Asia (5.0 µg/day, p < 0.001) and Africa (5.0 µg/day, p = 0.013). Participants from Continental Europe had the largest change (3.6 µg/day) between pre- and post-expansion, while those born in Asia had the smallest change (2.9 µg/day).

CONCLUSION

The Swedish fortification policy expansion had a positive potential impact on vitamin D intake during pregnancy, but the effect depended on the continent of origin. The potential impact was smallest for participants from Asia and Africa, indicating that the current Swedish fortification policy is most beneficial for individuals of European origin.

Vitamin D: Evidence-Based Health Benefits and Recommendations for Population Guidelines

Vitamin D offers numerous under-recognized health benefits beyond its well-known role in musculoskeletal health. It is vital for extra-renal tissues, prenatal health, brain function, immunity, pregnancy, cancer prevention, and cardiovascular health. Existing guidelines issued by governmental and health organizations are bone-centric and largely overlook the abovementioned extra-skeletal benefits and optimal thresholds for vitamin D. In addition, they rely on randomized controlled trials (RCTs), which seldom show benefits due to high baseline 25-hydroxyvitamin D [25(OH)D] concentrations, moderate supplementation doses, and flawed study designs. This review emphasizes the findings from prospective cohort studies showing that higher 25(OH)D concentrations reduce the risks of major diseases and mortality, including pregnancy and birth outcomes. Serum concentrations > 30 ng/mL (75 nmol/L) significantly lower disease and mortality risks compared to <20 ng/mL. With 25% of the U.S. population and 60% of Central Europeans having levels <20 ng/mL, concentrations should be raised above 30 ng/mL. This is achievable through daily supplementation with 2000 IU/day (50 mcg/day) of vitamin D3, which prevent diseases and deaths. Furthermore, a daily dose between 4000 and 6000 IU of vitamin D3 to achieve serum 25(OH)D levels between 40 and 70 ng/mL would provide greater protection against many adverse health outcomes. Future guidelines and recommendations should integrate the findings from observational prospective cohort studies and well-designed RCTs to improve public health and personalized care.

Mushrooms: a food-based solution to vitamin D deficiency to include in dietary guidelines

Vitamin D deficiency and insufficiency is a public health issue, with low dietary vitamin D intakes a contributing factor. Rates of vitamin D deficiency are 31% in Australia, and up to 72% in some regions globally. While supplementation is often prescribed as an alternative to additional sun exposure, complementary approaches including food-based solutions are needed. Yet, food-centric dietary guidelines are not always adequate for meeting vitamin D needs. Edible mushrooms such as Agaricus bisporus can produce over 100% of vitamin D recommendations (10 μg/day, Institute of Medicine) per 75 g serve (18 μg) on exposure to UV-light, with the vitamin D2 produced showing good stability during cooking and processing. However, mushrooms are overlooked as a vitamin D source in dietary guidelines. Our dietary modelling shows that four serves/week of UV-exposed button mushrooms can support most Australian adults in meeting vitamin D recommendations, and UV-exposed mushrooms have been found to increase vitamin D status in deficient individuals. While recent evidence suggests some differences between vitamin D2 and vitamin D3 in physiological activities, vitamin D2 from mushrooms can be part of a larger solution to increasing dietary vitamin D intakes, as well as an important focus for public health policy. Mushrooms exposed to UV represent an important tool in the strategic toolkit for addressing vitamin D deficiency in Australia and globally. Health authorities lead the recognition and promotion of mushrooms as a natural, vegan, safe, and sustainable vitamin D food source.

The Impact of Vitamin D and Its Dietary Supplementation in Breast Cancer Prevention: An Integrative Review

Vitamin D deficiency is currently a significant public health issue closely linked to numerous diseases, such as breast cancer. This study aims to determine the estimated optimal serum levels of vitamin D to have a protective effect against breast cancer, in addition to exploring the biological mechanisms and risk factors involved. A literature search of articles published in the last 5 years was conducted, and simple statistical analyses using mean and standard deviation were performed to calculate the average concentration of vitamin D from different available studies. It has been observed that serum levels of vitamin D ≥ 40.26 ng/mL ± 14.19 ng/mL could exert a protective effect against breast cancer. Additionally, various biological mechanisms, such as those related to the immune system, and risk factors like diet implicated in this relationship were elucidated. Consequently, it can be concluded that proper serum levels of vitamin D may have a protective effect against breast cancer, and dietary supplementation may be an appropriate procedure to achieve these optimal vitamin D concentrations.