Effect of Ultraviolet Light-Exposed Mushrooms on Vitamin D Status: Liquid Chromatography-Tandem Mass Spectrometry Reanalysis of Biobanked Sera from a Randomized Controlled Trial and a Systematic Review plus Meta-Analysis

Unearthing the therapeutic benefits of culinary-medicinal mushrooms for humans: Emerging sustainable bioresources of 21st century

Global interest in mushroom farming techniques has grown in the last few years. Despite not making up a large amount of the human diet at the moment, the nutritional worth of mushrooms has prompted their usage. The three main segments of the global mushroom industry are wild, culinary (edible), and medicinal mushrooms. The quality food that mushrooms provide can be utilized to build agricultural ecosystems that are more sustainable for increasing productivity and enhancing the effectiveness of resource usage. This is mostly because mushrooms can be utilized for the recycling of biomass and remains from crop production. Culinary-medicinal mushrooms are becoming more and more important because of their nutrient density, dietary value, and health advantages. Given its many bioactive components, which include polysaccharides, proteins, vitamins, minerals, dietary fiber, and secondary metabolites, mushrooms have been utilized extensively as health foods. These mushrooms exhibit pharmacological activities and possess prebiotic and antibacterial capabilities. This review provides information on the latest advancements in the sustainable cultivation of mushrooms, particularly with nontraditional substrates, and their potential therapeutic uses. Furthermore, some of the newest developments and difficulties in the production of mushrooms are explored.

Safety of vitamin D2 mushroom powder as a Novel food pursuant to Regulation (EU) 2015/2283 (NF 2020/2226)

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on vitamin D2 mushroom powder as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is produced from Agaricus bisporus mushroom powder that has been exposed to ultraviolet (UV) irradiation to induce the conversion of provitamin D2 (ergosterol) to vitamin D2 (ergocalciferol). The NF contains concentrations of vitamin D in the form of vitamin D2 in the range of 245-460 μg/g. The information provided on the production process, composition and specifications of the NF does not raise safety concerns. The applicant intends to add the NF as an ingredient in a variety of foods and beverages in amounts that result in either 1.2 or 2.4 μg vitamin D2 per 100 g or 100 mL of the food as consumed. The applicant also intends to add the NF in food supplements at a maximum of 15 μg vitamin D2/day for individuals above 1 year of age, as well as in foods for special medical purposes (FSMPs). The estimates for combined intake of vitamin D from the NF, the background diet and fortified foods, were below the ULs for vitamin D as established previously by the NDA Panel for children, adolescents and adults, i.e. 50 and 100 μg/day. The estimated combined vitamin D intake in infants (6-12 months) is also below the UL for vitamin D of 35 μg/day. The Panel considers that taking into account the composition of the NF and the proposed conditions of use, the consumption of the NF is not nutritionally disadvantageous for the proposed target population. The Panel concludes that the NF is safe under the proposed conditions of use.

The effect of vitamin D2 supplementation on vitamin D levels in humans: A time and dose-response meta-analysis of randomized controlled trials

BACKGROUND

Inconsistencies exist regarding the influence of vitamin D2 (ergocalciferol) supplementation on serum vitamin D levels. These inconsistencies could be attributed to numerous factors, such as dosage, baseline vitamin D levels, and duration of intervention. Hence, this dose-response meta-analysis of randomized controlled trials was conducted to assess the efficacy of vitamin D2 supplementation on vitamin D levels.

METHODS

Relevant studies were searched in PubMed/Medline, Web of Science, Embase, and Scopus, from their inception to 3 January 2023. Variable alterations were considered to calculate the pooled weighted mean difference (WMD) with 95% confidence interval (CI) using the random effects model.

RESULTS

Pooled results from 33 study arms demonstrated that Vitamin D2 treatment significantly increases total vitamin D concentrations (WMD: 11.47 ng/mL, 95 %CI: 9.29 to 13.64, p < 0.001), 25(OH)D2 concentrations (WMD: 11.40 ng/mL, 95 %CI: 4.72 to 18.09, p = 0.001), and 1,25(OH)D concentrations (WMD: 5.61 ng/mL, 95 %CI: 0.74 to 10.48, p = 0.024), but decreases 25(OH)D3 concentrations (WMD: -4.63 ng/mL, 95 %CI: -6.46 to -2.81, p < 0.001). In subgroup analyses, increase in total vitamin D concentrations was more significant in vitamin D2 doses >2000 IU/day (WMD: 13.82 ng/mL), studies with duration ≤12 weeks (WMD: 12.53 ng/mL), participants aged ≥60 years (WMD: 14.40 ng/mL), and trials with basal 25(OH)D concentrations <20 ng/mL (WMD: 11.47 ng/mL).

CONCLUSIONS

This meta-analysis indicates that the supplementation of vitamin D2 significantly increases the serum concentrations of total vitamin D, 25(OH)D2, and 1,25(OH)D, but decreases 25(OH)D3 concentrations. Careful consideration of patient characteristics, dosage, and treatment duration is recommended for vitamin D2 supplementation.

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

There has been growing interest in the potential of vitamin D food fortification in Europe as a means of addressing low vitamin D status. The WHO-FAO suggest that choosing a suitable food vehicle and ensuring the combination of the food vehicle and the fortificant will be efficacious and effective are of key importance to a successful food fortification programme. Our key objective was to conduct a systematic review and meta-analysis to investigate the effect of various animal- and plant-based food vehicles fortified with vitamin D (as D3 or D2) on circulating 25-hydroxyvitamin D [25(OH)D] concentrations. A list of prioritised food vehicles was established and we searched PubMed, Embase, Scopus and Web of Science for randomised controlled trials (RCTs) which used these vehicles individually, and which met prespecified criteria. The searches identified 49 papers which described suitable RCTs using vitamin D-fortified bread/savoury biscuits (n = 5), orange juice (n = 5), UV-mushrooms (n = 8), cheese (n = 3), yogurt (n = 5), fluid milk (n = 13), powdered milk (n = 5), eggs (n = 2), edible oils (n = 4), or breakfast cereal (n = 1). No suitable RCTs were identified for rice, maize flour, butter, margarine or dairy spreads, plant-based milk or yogurt alternatives. Random-effects meta-analyses of each food vehicle individually indicated weighted mean differences (WMD) in 25(OH)D in the range ∼9-35 nmol/L (3-15 RCT arms, depending on vehicle), and all statistically significant (P < 0.01-0.0001), with the exception of UV-mushrooms (P = 0.06). Heterogeneity was variable (I2 =33-99%, depending on vehicle), but subgroup analysis based on vitamer and dose reduced it in some instances. Sub-group analysis on the basis of whether the food vehicles were from plant-based or animal-based origin showed no significant difference in WMD (15.2 versus 15.9 nmol/L, respectively; P = 0.48). These results support the use of various animal- and plant-based food vehicles for vitamin D fortification to improve circulating 25(OH)D concentrations in populations. This work was registered with PROSPERO as CRD42023439883.

The Nutritional Benefit of UV-Exposed Mushrooms for the Dutch Population: Modeling the Addition of UV-Exposed Mushrooms to the Diet

Background

Mushrooms are rich in fiber and vitamins B and vitamin D when exposed to UV light and are sometimes used as a meat substitute. A modeling study showed that adding a mushroom portion (84 g/d) to the diet of an American population caused a significant improvement in the intake of several nutrients.

Objective

To study the association between habitual intake of mushrooms and nutrient intake and to assess the change in micronutrient intake with the modeled addition of 60 or 84 grams of UV-exposed mushrooms to the diet of the Dutch population, with a subanalysis on subjects with a low animal: plant protein ratio.

Methods

A modeling study was conducted in 3121 Dutch persons aged 9-80 y, using cross-sectional data from the Dutch National Food Consumption Survey 2012-2016. Linear regression was used to explore the association between habitual intake of mushrooms and nutrients. Habitual intake and nutritional adequacy were calculated before and after the modeled addition of mushrooms.

Results

A small association was observed between the habitual intake of mushrooms and the intake of copper, niacin, and vitamin B2 (beta ranging from 0.002 to 0.039). The modeled addition of UV-exposed mushrooms increased the intakes of plant protein (by 5-7%), fiber (4-6%), niacin (10-20%), vitamin D (176-388%), folate (11-17%), potassium (6-10%), and copper (29-48%). Nutritional adequacy also improved significantly. For subjects with a low animal:plant protein ratio, the added mushrooms increased the intakes of niacin (11-22%), potassium (6-11%), and vitamin D (190-445%).

Conclusions

Consumption of mushrooms contributes to higher intakes of copper, niacin, and vitamin B2. Addition of UV-exposed mushrooms to the diet of the Dutch further improves nutrient intakes and, most notably, vitamin D, especially for people with low animal food consumption.

Effect of Ultraviolet Irradiation on Vitamin D in Commonly Consumed Mushrooms in Thailand

This study examined the effect and stability of ultraviolet B (UV-B) irradiation and subsequent cooking on vitamin D content in commonly consumed mushrooms in Thailand. Eight varieties of mushrooms were exposed to two-sided UV-B lamps for up to 3 h in a patented cabinet, followed by vitamin D content analysis. Thereafter, the four mushroom varieties with the highest vitamin D content were exposed to UV irradiation, cooked, and analyzed for various forms of vitamin D using LC-MS-MS. The results showed that vitamin D2 in all varieties of mushrooms significantly increased (p < 0.05) after UV-B irradiation according to the exposure time. The highest level of vitamin D2 was found in enokitake mushrooms. In addition, 25-OH D2 and vitamin D4 contents increased after UV-B irradiation in enokitake mushrooms. The vitamin D2 true retention in all cooked mushrooms ranged from 53 to 89% and was highest in stir-fried mushrooms. With economic investment, the two-sided UV-B cabinet has the potential to increase the vitamin D content in commercial mushroom production.

The Retention of Vitamin D2 and 25-Hydroxyvitamin D2 in Pulse UV-Irradiated Dried Button Mushrooms (Agaricus bisporus) after 12 Months of Storage

Fresh mushrooms exposed to ultraviolet (UV) radiation prior to drying generate high concentrations of vitamin D2. The aim of this study was to determine the retention of D vitamers in mushrooms that were pulse UV irradiated, then air dried, and stored for up to 12 months. Fresh button mushrooms (A. bisporus) were exposed to pulsed UV radiation (dose 200 mJ/cm2, peak of 17.5 W/cm2), air dried and vacuum sealed before being stored in the dark at room temperature. After storage, samples were freeze dried and quantified for D vitamers using triple quadrupole mass spectrometry. After 3, 6 and 12 months of storage, there was 100% (11.0 ± 0.8 µg/g dry weight (DW), 93% (10.1 ± 0.6 µg/g DW) and 58% (5.5 ± 0.6 µg/g DW) retention of vitamin D2 and 88% (0.14 ± 0.01 µg/g DW), 71% (0.11 ± 0.01 µg/g DW) and 68% (0.1 ± 0.01 µg/g DW) retention of 25-hydroxyvitamin D2 (25(OH)D2), respectively. Compared to the irradiated dried mushrooms that were not stored, the D vitamer concentration was statistically significantly lower (p < 0.05) at 6 and 12 months for 25(OH)D2 and at 12 months for vitamin D2. Sufficient vitamin D2 (99 µg) remained after 12 months storage to provide at least 100% of daily dietary vitamin D requirements in a 20 g serving.

UVB-exposed wheat germ oil increases serum 25-hydroxyvitamin D2 without improving overall vitamin D status: a randomized controlled trial

PURPOSE

This study investigated whether UVB-exposed wheat germ oil (WGO) is capable to improving the vitamin D status in healthy volunteers.

METHODS

A randomized controlled human-intervention trial in parallel design was conducted in Jena (Germany) between February and April. Ultimately, 46 healthy males and females with low mean 25-hydroxyvitamin D (25(OH)D) levels (34.9 ± 10.6 nmol/L) were randomized into three groups receiving either no WGO oil (control, n = 14), 10 g non-exposed WGO per day (- UVB WGO, n = 16) or 10 g WGO, which was exposed for 10 min to ultraviolet B-light (UVB, intensity 500-630 µW/cm2) and provided 23.7 µg vitamin D (22.9 µg vitamin D2 and 0.89 µg vitamin D3) (+ UVB WGO, n = 16) for 6 weeks. Blood was obtained at baseline, after 3 and 6 weeks and analyzed for serum vitamin D-metabolite concentrations via LC-MS/MS.

RESULTS

Participants who received the UVB-exposed WGO were characterized by an increase of circulating 25(OH)D2 after 3 and 6 weeks of intervention. However, the 25(OH)D3 concentrations decreased in the + UVB WGO group, while they increased in the control groups. Finally, the total 25(OH)D concentration (25(OH)D2 + 25(OH)D3) in the + UVB WGO group was lower than that of the non-WGO receiving control group after 6 weeks of treatment. In contrast, circulating vitamin D (vitamin D2 + vitamin D3) was higher in the + UVB WGO group than in the control group receiving no WGO.

CONCLUSION

UVB-exposed WGO containing 23.7 µg vitamin D can increase 25(OH)D2 levels but do no improve total serum levels of 25(OH)D of vitamin D-insufficient subjects.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03499327 (registered, April 13, 2018).

Implementation strategies for improving vitamin D status and increasing vitamin D intake in the UK: current controversies and future perspectives: proceedings of the 2nd Rank Prize Funds Forum on vitamin D

A multi-disciplinary expert group met to discuss vitamin D deficiency in the UK and strategies for improving population intakes and status. Changes to UK Government advice since the 1st Rank Forum on Vitamin D (2009) were discussed, including rationale for setting a reference nutrient intake (10 µg/d; 400 IU/d) for adults and children (4+ years). Current UK data show inadequate intakes among all age groups and high prevalence of low vitamin D status among specific groups (e.g. pregnant women and adolescent males/females). Evidence of widespread deficiency within some minority ethnic groups, resulting in nutritional rickets (particularly among Black and South Asian infants), raised particular concern. Latest data indicate that UK population vitamin D intakes and status reamain relatively unchanged since Government recommendations changed in 2016. Vitamin D food fortification was discussed as a potential strategy to increase population intakes. Data from dose-response and dietary modelling studies indicate dairy products, bread, hens' eggs and some meats as potential fortification vehicles. Vitamin D3 appears more effective than vitamin D2 for raising serum 25-hydroxyvitamin D concentration, which has implications for choice of fortificant. Other considerations for successful fortification strategies include: (i) need for 'real-world' cost information for use in modelling work; (ii) supportive food legislation; (iii) improved consumer and health professional understanding of vitamin D's importance; (iv) clinical consequences of inadequate vitamin D status and (v) consistent communication of Government advice across health/social care professions, and via the food industry. These areas urgently require further research to enable universal improvement in vitamin D intakes and status in the UK population.

Yeast as a biological platform for vitamin D production: A promising alternative to help reduce vitamin D deficiency in humans

Vitamin D is an important human hormone, known primarily to be involved in the intestinal absorption of calcium and phosphate, but it is also involved in various non-skeletal processes (molecular, cellular, immune, and neuronal). One of the main health problems nowadays is the vitamin D deficiency of the human population due to lack of sun exposure, with estimates of one billion people worldwide with vitamin D deficiency, and the consequent need for clinical intervention (i.e., prescription of pharmacological vitamin D supplements). An alternative to reduce vitamin D deficiency is to produce good dietary sources of it, a scenario in which the yeast Saccharomyces cerevisiae seems to be a promising alternative. This review focuses on the potential use of yeast as a biological platform to produce vitamin D, summarizing both the biology aspects of vitamin D (synthesis, ecology and evolution, metabolism, and bioequivalence) and the work done to produce it in yeast (both for vitamin D₂ and for vitamin D₃ ), highlighting existing challenges and potential solutions. This article is protected by copyright. All rights reserved.

Vitamin D biomarkers for Dietary Reference Intake development in children: a systematic review and meta-analysis

BACKGROUND

Circulating 25-hydroxyvitamin D [25(OH)D] has been the accepted vitamin D exposure/intake biomarker of choice within recent DRI exercises, but use of other vitamin D-related biomarkers as well as functional markers has been suggested. These may be of value in future vitamin D DRI exercises, such as the FAO/WHO's one for young children.

OBJECTIVES

To systematically review the usefulness of circulating 25(OH)D, parathyroid hormone (PTH), free and bioavailable 25(OH)D, C3-epimer of 25(OH)D, vitamin D3, 24,25-dihydroxyvitamin D [24,25(OH)2D], and bone turnover markers and calcium absorption as vitamin D biomarkers for DRI development in children.

METHODS

Methods included structured searches of published articles, full-text reviews, data extraction, quality assessment, meta-analysis, and random-effects meta-regression.

RESULTS

Fifty-nine vitamin D supplementation randomized controlled trials (RCTs) were included (39 in infants/children as the priority group and the remainder in adults since pediatric studies were absent/limited). Vitamin D supplementation significantly raised circulating 25(OH)D in infants and children, but the response was highly heterogeneous [weighted mean difference (WMD): 27.7 nmol/L; 95% CI: 22.9, 32.5; 27 RCTs; I2 = 93%]. Meta-regression suggested an increase by 1.7 nmol/L (95% CI: 0.7, 2.6) in serum 25(OH)D per each 100-IU increment in vitamin D intake (P = 0.0005). Vitamin D supplementation had a significant effect on circulating 24,25(OH)2D (WMD: 3.4 nmol/L; 95% CI: 2.4, 4.5; 13 RCTs; I2 = 95%), with a dose-response relation (+0.15 nmol/L per 100 IU; 95% CI: -0.01, 0.29). With circulating PTH, although there was a significant effect of vitamin D on WMD (P = 0.05), there was no significant dose-response relation (P = 0.32). Pediatric data were too limited in relation to the usefulness of the other biomarkers.

CONCLUSIONS

Circulating 25(OH)D may be a useful biomarker of vitamin D exposure/intake for DRI development in infants and children. Circulating 24,25(OH)2D also showed some promise, but further data are needed, especially in infants and children.

Safety of Vitamin D Food Fortification and Supplementation: Evidence from Randomized Controlled Trials and Observational Studies

The safety considerations of food-based solutions for vitamin D deficiency prevention, such as fortification and supplementation, are critical. On the basis of collective data from 20 randomized controlled trials (RCTs) and 20 national healthy surveys, as well as prospective cohort studies (PCSs) across the ODIN project (“Food-based solutions for optimal vitamin D nutrition and health through the life cycle”, FP7-613977), we analyzed the potential safety issues arising from vitamin D intakes and/or supplementation. These adverse consequences included high serum 25-hydroxyvitamin D (S-25(OH)D) concentrations (>125 nmol/L), high serum calcium concentrations, and vitamin D intakes in excess of the tolerable upper intake levels (ULs). In the RCTs (n = 3353, with vitamin D doses from 5–175 µg/day), there were no reported adverse effects. The prevalence of high S-25(OH)D was <10% when vitamin D supplements were administered, and <0.1% for fortified foods. Elevated serum calcium was observed among <0.5% in both administration types. No ODIN RCT participants exceeded the age-specific ULs. In observational studies (n = 61,082), the prevalence of high 25(OH)D among children/adolescents, adults, and older adults was <0.3%, with no evidence of adverse effects. In conclusion, high S-25(OH)D concentrations >125 nmol/L were rare in the RCTs and PCSs, and no associated adverse effects were observed.

The future is bright: Biofortification of common foods can improve vitamin D status

Vitamin D deficiency is a global concern, linked to suboptimal musculoskeletal health and immune function, with status inadequacies owing to variations in UV dependent cutaneous synthesis and limited natural dietary sources. Endogenous biofortification, alongside traditional fortification and supplement usage is urgently needed to address this deficit. Evidence reviewed in the current article clearly demonstrates that feed modification and UV radiation, either independently or used in combination, effectively increases vitamin D content of primary produce or ingredients, albeit in the limited range of food vehicles tested to date (beef/pork/chicken/eggs/fish/bread/mushrooms). Fewer human trials have confirmed that consumption of these biofortified foods can increase circulating 25-hydroxyvitamin D [25(OH)D] concentrations (n = 10), which is of particular importance to avoid vitamin D status declining to nadir during wintertime. Meat is an unexplored yet plausible food vehicle for vitamin D biofortification, owing, at least in part, to its ubiquitous consumption pattern. Consumption of PUFA-enriched meat in human trials demonstrates efficacy (n = 4), lighting the way for exploration of vitamin D-biofortified meats to enhance consumer vitamin D status. Response to vitamin D-biofortified foods varies by food matrix, with vitamin D₃-enriched animal-based foods observing the greatest effect in maintaining or elevating 25(OH)D concentrations. Generally, the efficacy of biofortification appears to vary dependent upon vitamer selected for animal feed supplementation (vitamin D₂ or D₃, or 25(OH)D), baseline participant status and the bioaccessibility from the food matrix. Further research in the form of robust human clinical trials are required to explore the contribution of biofortified foods to vitamin D status.

Oral Intake of Lumisterol Affects the Metabolism of Vitamin D

SCOPE

The treatment of food with ultraviolet-B (UV-B) light to increase the vitamin D content is accompanied by the formation of photoisomers, such as lumisterol2 . The physiological impact of photoisomers is largely unknown.

METHODS AND RESULTS

Three groups of C57Bl/6 mice are fed diets containing 50 µg kg-1 deuterated vitamin D3 with 0, 50 (moderate-dose) or 2000 µg kg-1 (high-dose) lumisterol2 for four weeks. Considerable quantities of lumisterol2 and vitamin D2 are found in the plasma and tissues of mice fed with 2000 µg kg-1 lumisterol2 but not in those fed 0 or 50 µg kg-1 lumisterol2 . Mice fed with 2000 µg kg-1 lumisterol2 showed strongly reduced deuterated 25-hydroxyvitamin D3 (-50%) and calcitriol (-80%) levels in plasma, accompanied by downregulated mRNA abundance of cytochrom P450 (Cyp)27b1 and upregulated Cyp24a1 in the kidneys. Increased tissue levels of vitamin D2 were also seen in mice in a second study that are kept on a diet with 0.2% UV-B exposed yeast versus those fed 0.2% untreated yeast containing iso-amounts of vitamin D2 .

CONCLUSION

High doses of lumisterol2 can enter the body, induce the formation of vitamin D2 , reduce the levels of 25(OH)D3 and calcitriol and strongly impact the expression of genes involved in the degradation and synthesis of bioactive vitamin D.

Assessing the impact of a mushroom-derived food ingredient on vitamin D levels in healthy volunteers

BACKGROUND

Prevalence of vitamin D insufficiency/deficiency has been noted in athletic populations, although less is known about recreationally active individuals. Biofortification of natural food sources (e.g. UV radiated mushrooms) may support vitamin D status and is therefore of current scientific and commercial interest. The aim of this study was to assess the impact of a mushroom-derived food ingredient on vitamin D status in recreationally active, healthy volunteers.

METHODS

Twenty-eight participants were randomly assigned to either: 25 μg (1000 IU) encapsulated natural mushroom-derived vitamin D₂; matched-dose encapsulated vitamin D₃ or placebo (PL) for 12 weeks. Venous blood samples were collected at baseline, week 6 and 12 for analysis of serum 25(OH)D₂ and 25(OH)D₃ using liquid chromatography mass spectrometry. Habitual dietary intake and activity were monitored across the intervention.

RESULTS

Vitamin D status (25(OH)D_TOTAL) was significantly increased with vitamin D₃ supplementation from 46.1 ± 5.3 nmol·L^- 1 to 88.0 ± 8.6 nmol·L^- 1 (p < 0.0001) across the intervention, coupled with an expected rise in 25(OH)D₃ concentrations from 38.8 ± 5.2 nmol·L^- 1 to 82.0 ± 7.9 nmol·L^- 1 (p < 0.0001). In contrast, D₂ supplementation increased 25(OH)D₂ by + 347% (7.0 ± 1.1 nmol·L^- 1 to 31.4 ± 2.1 nmol·L^- 1, p < 0.0001), but resulted in a - 42% reduction in 25(OH)D₃ by week 6 (p = 0.001). A net + 14% increase in 25(OH)D_TOTAL was established with D₂ supplementation by week 12 (p > 0.05), which was not statistically different to D₃. Vitamin D status was maintained with PL, following an initial - 15% reduction by week 6 (p ≤ 0.046 compared to both supplement groups).

CONCLUSIONS

The use of a UV radiated mushroom food ingredient was effective in maintaining 25(OH)D_TOTAL in healthy, recreationally active volunteers. This may offer an adjunct strategy in supporting vitamin D intake. However, consistent with the literature, the use of vitamin D₃ supplementation likely offers benefits when acute elevation in vitamin D status is warranted.

Is There Scope for a Novel Mycelium Category of Proteins alongside Animals and Plants?

In the 21st century, we face a troubling trilemma of expanding populations, planetary and public wellbeing. Given this, shifts from animal to plant food protein are gaining momentum and are an important part of reducing carbon emissions and consumptive water use. However, as this fast-pace of change sets in and begins to firmly embed itself within food-based dietary guidelines (FBDG) and food policies we must raise an important question-is now an opportunistic time to include other novel, nutritious and sustainable proteins within FBGD? The current paper describes how food proteins are typically categorised within FBDG and discusses how these could further evolve. Presently, food proteins tend to fall under the umbrella of being 'animal-derived' or 'plant-based' whilst other valuable proteins i.e., fungal-derived appear to be comparatively overlooked. A PubMed search of systematic reviews and meta-analytical studies published over the last 5 years shows an established body of evidence for animal-derived proteins (although some findings were less favourable), plant-based proteins and an expanding body of science for mycelium/fungal-derived proteins. Given this, along with elevated demands for alternative proteins there appears to be scope to introduce a 'third' protein category when compiling FBDG. This could fall under the potential heading of 'fungal' protein, with scope to include mycelium such as mycoprotein within this, for which the evidence-base is accruing.

Potential of Chlorella as a Dietary Supplement to Promote Human Health

Chlorella is a green unicellular alga that is commercially produced and distributed worldwide as a dietary supplement. Chlorella products contain numerous nutrients and vitamins, including D and B12, that are absent in plant-derived food sources. Chlorella contains larger amounts of folate and iron than other plant-derived foods. Chlorella supplementation to mammals, including humans, has been reported to exhibit various pharmacological activities, including immunomodulatory, antioxidant, antidiabetic, antihypertensive, and antihyperlipidemic activities. Meta-analysis on the effects of Chlorella supplementation on cardiovascular risk factors have suggested that it improves total cholesterol levels, low-density lipoprotein cholesterol levels, systolic blood pressure, diastolic blood pressure, and fasting blood glucose levels but not triglycerides and high-density lipoprotein cholesterol levels. These beneficial effects of Chlorella might be due to synergism between multiple nutrient and antioxidant compounds. However, information regarding the bioactive compounds in Chlorella is limited.

Vitamin D Deficiency: Defining, Prevalence, Causes, and Strategies of Addressing

There are variable definitions of vitamin D deficiency, based on different thresholds of serum 25-hydroxyvitamin D (25(OH)D); this has a major bearing on the prevalence estimates of vitamin D deficiency and consequently on the magnitude of the public health issue of low vitamin D status. Despite this, there is widespread acknowledgement of the presence of vitamin D deficiency, even using the most conservative serum 25(OH)D threshold of < 25/30 nmol/L, in both low- and high-income country setting and the pressing need to address this deficiency. While ultraviolet B-rich sunlight stimulates synthesis of vitamin D in skin, there are environmental factors and personal characteristics which prevent or impede such dermal synthesis. There are several complexities and concerns in advocating sun exposure as a public health approach for increasing vitamin D status. This places increased emphasis on addressing vitamin D deficiency through dietary means. However, naturally rich sources of vitamin D are few and infrequently consumed, and nutrition surveillance data from various countries have indicated that habitual vitamin D intakes in the population are much lower than the recommendations. There are a number of strategies that can be considered for the control of micronutrient malnutrition, these include (i) increasing the diversity of foods consumed, (ii) food fortification, and (iii) supplementation. The present narrative review will consider these strategies for addressing low dietary vitamin D intake and consequently lowering the risk of vitamin D deficiency.

Current vitamin D status in European and Middle East countries and strategies to prevent vitamin D deficiency: a position statement of the European Calcified Tissue Society

Vitamin D deficiency (serum 25-hydroxyvitamin D (25(OH)D) <50 nmol/L or 20 ng/mL) is common in Europe and the Middle East. It occurs in <20% of the population in Northern Europe, in 30-60% in Western, Southern and Eastern Europe and up to 80% in Middle East countries. Severe deficiency (serum 25(OH)D <30 nmol/L or 12 ng/mL) is found in >10% of Europeans. The European Calcified Tissue Society (ECTS) advises that the measurement of serum 25(OH)D be standardized, for example, by the Vitamin D Standardization Program. Risk groups include young children, adolescents, pregnant women, older people (especially the institutionalized) and non-Western immigrants. Consequences of vitamin D deficiency include mineralization defects and lower bone mineral density causing fractures. Extra-skeletal consequences may be muscle weakness, falls and acute respiratory infection, and are the subject of large ongoing clinical trials. The ECTS advises to improve vitamin D status by food fortification and the use of vitamin D supplements in risk groups. Fortification of foods by adding vitamin D to dairy products, bread and cereals can improve the vitamin D status of the whole population, but quality assurance monitoring is needed to prevent intoxication. Specific risk groups such as infants and children up to 3 years, pregnant women, older persons and non-Western immigrants should routinely receive vitamin D supplements. Future research should include genetic studies to better define individual vulnerability for vitamin D deficiency, and Mendelian randomization studies to address the effect of vitamin D deficiency on long-term non-skeletal outcomes such as cancer.

Contribution of nutrition science to the vitamin D field-Clarity or confusion?

Recent opinion pieces have questioned whether nutrition science is fit for purpose, suggesting that the evidence-base for dietary recommendations is populated with poor quality science and unresolved controversy. Nutrition science is accused of not keeping up with the times and making little real-world progress to stem the growing global malnutrition crisis, by failing to apply cutting-edge techniques to nutrition problems. Nutritional epidemiology has been blamed for harming public health nutrition and the public perception of science itself, by selectively reporting biased, confounded data. Focussed on obesity and associated disorders and hunger, these articles do not refer to micronutrient deficiencies or advances in micronutrient research. There is a serious public health problem of low vitamin D status. Given that the field of vitamin D has experienced an exponential increase in peer-reviewed publications over the last 50 years, it seems timely that we take these cues to reflect upon whether the expanded body of scientific literature has contributed to a deeper knowledge of vitamin D in health and disease, leading to improved nutrition policy and patient care, or whether it has led to so much confusion and controversy that progress has been impeded. We consider whether the accusations of poor science and biased reporting levelled at nutrition science are evident within the vitamin D nutrition research area and whether they have compromised dietary recommendations for vitamin D. In evaluating whether reformation is required, we discuss the confusion and controversy within the field and signpost common ground within the vitamin D community. We outline vitamin D nutrition research that has presented strategies for vitamin D deficiency prevention within the population, particularly using food first approaches that could extend beyond high income settings to low- and middle-income countries. Finally, we encourage government and industry to implement technical advances and drive real-world progress.

Vitamin-D2 treatment-associated decrease in 25(OH)D3 level is a reciprocal phenomenon: a randomized controlled trial

BACKGROUND

Vitamin-D2 (D2) treatment has been associated with a decrease in 25-hydroxy (25(OH)) vitamin-D3 (D3) level, suggesting that D3 treatment would be preferred to raise total 25(OH) vitamin-D (D) level. We postulated that D2 treatment-associated decrease in 25(OH)D3 level is related to the increase in 25(OH)D level rather than being D2-specific, and thus there would be a similar D3 treatment-associated decrease in 25(OH)D2 level.

METHODS

Fifty volunteers were block-randomized to 50,000 IU D2 or placebo orally once (study-1) and fifty volunteers received 50,000 IU D2 orally once and 4 days later block-randomized to 50,000 IU D3 or placebo orally once (study-2). Interventions were concealed from volunteers and research coordinators and blindly-administered. Serum 25(OH)D2 and 25(OH)D3 levels were blindly-determined at baseline and days 14, 28, 42, and 56, post-randomization by high performance liquid chromatography assay. Results of 97 participants were analyzed. Primary outcome measure was day-28 D2-associated change in 25(OH)D3 level in study-1 and D3-associated change in 25(OH)D2 level in study-2, adjusted for baseline levels.

RESULTS

Mean (95% confidence interval) difference between the active and placebo arms in the decrease in day-28 25(OH)D3 (study-1) and 25(OH)D2 (study-2) levels was 13.2 (9.7 to 16.6) and 9.8 (5.2 to 14.4) nmol/L, respectively. Corresponding differences at day-56 were 10.8 (6.8 to 14.8) and 1.7 (- 7.6 to 11.1) nmol/L, respectively. The difference between the placebo and active arms in area-under-the-curve at day-28 (AUC₂₈) and day-56 (AUC₅₆) were 262.3 (197.8 to 326.7) and 605.1 (446.3 to 784.0) for 25(OH)D3 (study-1) and 282.2 (111.2 to 453.3) and 431.2 (179.3 to 683.2) nmol.d/L for 25(OH)D2 (study-2), respectively. There were significant correlations between day-28 changes in 25(OH)D2 and 25(OH)D3 levels in study-1 (rho = - 0.79, p < 0.001) and study-2 (rho = - 0.36, p = 0.01), and between day-28 changes in 25(OH)D2 level and baseline 25(OH)D level in study-2 (rho = - 0.42, p = 0.003).

CONCLUSIONS

Compared to placebo, D3 treatment is associated with a decrease in 25(OH)D2 level similar in magnitude to D2-treatment associated decrease in 25(OH)D3 level; however, the D3-placebo difference in 25(OH)D2 level is shorter-lasting. Changes in 25(OH)D2 and 25(OH)D3 levels are correlated with each other and with baseline 25 (OH) D levels, suggesting a common regulatory mechanism.

TRIAL REGISTRATION

ClinicalTrial.gov identifier: NCT03035084 (registered January 27, 2017).

Summary Outcomes of the ODIN Project on Food Fortification for Vitamin D Deficiency Prevention

Food-based solutions for optimal vitamin D nutrition and health through the life cycle (ODIN) was a cross-disciplinary, collaborative project, including 30 partners from 19 countries, which aimed to develop evidence-based solutions to prevent low vitamin D status (25-hydroxyvitamin D (25(OH)D) < 30 nmol/L) using a food-first approach. This paper provides a summary overview of some of the important ODIN outcomes and outlines some outstanding data requirements. In a study of almost 56,000 individuals, the first internationally standardised dataset of vitamin D status showed that 13% of EU residents overall, across a latitude gradient of 35° N to 69° N, had serum 25(OH)D < 30 nmol/L and 40% were < 50 nmol/L. The risk of low vitamin D status was several-fold higher among persons of ethnic minority. However, additional data from quality bio-banked sera would be required to improve these estimates. To address the question of dietary requirements for vitamin D among under-researched life-stage and population groups, four dose-response RCTs conducted in Northern Europe showed that vitamin D₃ intakes of 8 and 13 μg/day prevented 25(OH)D decreasing below 30 nmol/L in white children and adolescents and 20 and 30 μg/day, respectively, achieved ≥50 nmol/L. Among white women during pregnancy, 30 μg/day is required to prevent umbilical cord 25(OH)D, representing new-born vitamin D status, below 25 nmol/L. While 8 μg/day protected white women in Finland at the 30 nmol/L cut-off, 18 μg/day was needed by women of East African descent to prevent 25(OH)D decreasing below 30 nmol/L during wintertime. Replicate RCTs are needed in young children <5 years and in school-age children, teens and pregnant women of ethnic minority. Using a series of food production studies, food-based RCTs and dietary modelling experiments, ODIN research shows that diverse fortification strategies could safely increase population intakes and prevent low vitamin D status. Building on this solid technological platform, implementation research is now warranted to scale up interventions in real-world settings to eradicate vitamin D deficiency.

Global prevalence and disease burden of vitamin D deficiency: a roadmap for action in low- and middle-income countries

Vitamin D is an essential nutrient for bone health and may influence the risks of respiratory illness, adverse pregnancy outcomes, and chronic diseases of adulthood. Because many countries have a relatively low supply of foods rich in vitamin D and inadequate exposure to natural ultraviolet B (UVB) radiation from sunlight, an important proportion of the global population is at risk of vitamin D deficiency. There is general agreement that the minimum serum/plasma 25-hydroxyvitamin D concentration (25(OH)D) that protects against vitamin D deficiency-related bone disease is approximately 30 nmol/L; therefore, this threshold is suitable to define vitamin D deficiency in population surveys. However, efforts to assess the vitamin D status of populations in low- and middle-income countries have been hampered by limited availability of population-representative 25(OH)D data, particularly among population subgroups most vulnerable to the skeletal and potential extraskeletal consequences of low vitamin D status, namely exclusively breastfed infants, children, adolescents, pregnant and lactating women, and the elderly. In the absence of 25(OH)D data, identification of communities that would benefit from public health interventions to improve vitamin D status may require proxy indicators of the population risk of vitamin D deficiency, such as the prevalence of rickets or metrics of usual UVB exposure. If a high prevalence of vitamin D deficiency is identified (>20% prevalence of 25(OH)D < 30 nmol/L) or the risk for vitamin D deficiency is determined to be high based on proxy indicators (e.g., prevalence of rickets >1%), food fortification and/or targeted vitamin D supplementation policies can be implemented to reduce the burden of vitamin D deficiency-related conditions in vulnerable populations.

Vitamin D-biofortified beef: A comparison of cholecalciferol with synthetic versus UVB-mushroom-derived ergosterol as feed source

This study investigates dietary fortification of heifer feeds with cholecalciferol and ergocalciferol sources and effects on beef total vitamin D activity, vitamer, respective 25-hydroxymetabolite contents, and meat quality. Thirty heifers were allocated to one of three dietary treatments [(1) basal diet + 4000 IU of vitamin D₃ (Vit D₃); (2) basal diet + 4000 IU of vitamin D₂ (Vit D₂); and (3) basal diet + 4000 IU of vitamin D₂-enriched mushrooms (Mushroom D₂)] for a 30 day pre-slaughter period. Supplementation of heifer diets with Vit D₃ yielded higher (p < 0.001) Longissimus thoracis (LT) total vitamin D activity (by 38-56%; p < 0.05) and serum 25-OH-D concentration (by 20-36%; p < 0.05), compared to that from Vit D₂ and Mushroom D₂ supplemented animals. Irrespective of vitamin D source, carcass characteristics, sensory and meat quality parameter were unaffected (p > 0.05) by the dietary treatments. In conclusion, vitamin D₃ biofortification of cattle diets is the most efficacious way to enhance total beef vitamin D activity.

Is vitamin D deficiency a public health concern for low middle income countries? A systematic literature review

PURPOSE

Vitamin D deficiency has been receiving increasing attention as a potential public health concern in low and lower-middle income countries (LMICs), of which there are currently 83. We aimed to conduct a comprehensive systematic literature review (SLR) of available data on vitamin D status and prevalence of vitamin D deficiency in all 83 LMICs.

METHODS

We followed the general methodology for SLRs in the area of serum 25-hydroxyvitamin D. Highest priority was placed on identifying relevant population-based studies, followed by cross-sectional studies, and to a lesser extent case-control studies. We adopted the public health convention that a prevalence of vitamin D deficiency (serum 25-hydroxyvitamin D < 25/30 nmol/L) at > 20% in the entire population and/or at-risk population subgroups (infants, children, women of child-bearing age, pregnancy) constitutes a public health issue that may warrant intervention.

RESULTS

Our SLR revealed that of the 83 LMICs, 65% (n = 54 countries) had no published studies with vitamin D data suitable for inclusion. Using data from the remaining third, a number of LMICs had evidence of excess burden of vitamin D deficiency in one or more population subgroup(s) using the above convention (Afghanistan, Pakistan, India, Tunisia and Mongolia) as well as possibly other LMICs, albeit with much more limited data. Several LMICs had no evidence of excess burden.

CONCLUSION

Vitamin D deficiency is a public health issue in some, but certainly not all, LMICs. There is a clear need for targeting public health strategies for prevention of vitamin D deficiency in those LMICs with excess burden.

Vitamin D deficiency as a public health issue: using vitamin D2 or vitamin D3 in future fortification strategies

The role of vitamin D in supporting the growth and maintenance of the skeleton is robust; with recent research also suggesting a beneficial link between vitamin D and other non-skeletal health outcomes, including immune function, cardiovascular health and cancer. Despite this, vitamin D deficiency remains a global public health issue, with a renewed focus in the UK following the publication of Public Health England's new Dietary Vitamin D Requirements. Natural sources of vitamin D (dietary and UVB exposure) are limited, and thus mechanisms are needed to allow individuals to achieve the new dietary recommendations. Mandatory or voluntary vitamin D food fortification may be one of the mechanisms to increase dietary vitamin D intakes and subsequently improve vitamin D status. However, for the food industry and public to make informed decisions, clarity is needed as to whether vitamins D2 and D3 are equally effective at raising total 25-hydroxyvitamin D (25(OH)D) concentrations as the evidence thus far is inconsistent. This review summarises the evidence to date behind the comparative efficacy of vitamins D2 and D3 at raising 25(OH)D concentrations, and the potential role of vitamin D food fortification as a public health policy to support attainment of dietary recommendations in the UK. The comparative efficacy of vitamins D2 and D3 has been investigated in several intervention trials, with most indicating that vitamin D3 is more effective at raising 25(OH)D concentrations. However, flaws in study designs (predominantly under powering) mean there remains a need for a large, robust randomised-controlled trial to provide conclusive evidence, which the future publication of the D2-D3 Study should provide (BBSRC DRINC funded: BB/I006192/1). This review also highlights outstanding questions and gaps in the research that need to be addressed to ensure the most efficacious and safe vitamin D food fortification practices are put in place. This further research, alongside cost, availability and ethical considerations (vitamin D3 is not suitable for vegans), will be instrumental in supporting government, decision-makers, industry and consumers in making informed choices about potential future vitamin D policy and practice.

Differential effects of vitamin D2 and D3 supplements on 25-hydroxyvitamin D level are dose, sex, and time dependent: a randomized controlled trial

BACKGROUND

Vitamin D (D) supplements are indispensable for its world-wide deficiency. Controversy continues on ergocalciferol (D2) and cholecalciferol (D3) relative potency as well as on dosing-schedule and sex role in raising 25-hydroxy D (25(OH)D) level, the best indicator of D status.

METHODS

We randomized 279 adults to daily D2, D3, D2/D3, or placebo; 2-weekly D2 or D3; or 4-weekly D2 or D3 (250,000 IU over/140 days). Randomization sequence, stratified by body-mass-index (BMI) and sex, was concealed from study coordinators and participants who were then blinded to capsules' content. D2, D3, 25(OH)D2, and 25(OH)D3 Serum levels were determined blindly on days 0,1,2,3,4,7,14, and 2-weekly thereafter by high performance liquid chromatography assay. The results of 269 participants were available for analysis. Primary endpoint was area-under-the-curve (AUC) of 25(OH)D (25(OH)D2 + 25(OH)D3) adjusted for sex, BMI, and baseline 25(OH)D level.

RESULTS

Mean(SD) age was 33.0(8.5) year, 41% were males, and 85% completed follow-up. Baseline 25(OH)D level was 39.8(11.9) and increased by 3.3(11.6) and 28.6(16.3) nmol/L, in the placebo and active-treatment groups, respectively. AUC from day 0 to 140 (AUC₁₄₀) of 25(OH)D was 40% (D3 daily) to 55% (D3 2-weekly) higher with active-treatment than placebo (p < 0.001). 25(OH)D2 AUC₁₄₀ was higher in daily than 2-weekly (17%, p = 0.006) and 4-weekly (20%, p = 0.001) D2-treated groups. 25(OH)D3 AUC₁₄₀ was lower in daily than 2-weekly (11%, p = 0.002) and 4-weekly D3-treated groups (10%, p = 0.008). In D2-treated groups, there was 16.4 nmol/L decrease in 25(OH)D3 level that correlated (p < 0.001) with 25(OH)D2 level increase (r = 0.48) and baseline 25(OH)D level (r = 0.58), in one participant with measurable baseline 25(OH)D2 level, D3 caused a similar decrease in 25(OH)D2 level, while in the D2/D3-treated group, 25(OH)D3 level didn't increase. Incremental AUC from day 0 to 7 (AUC₇) of D3 and 25(OH)D3 in D3-treated groups were 118-243% higher and 31-39% lower, respectively, than incremental AUC₇ of D2 and 25(OH)D2 in D2-treated groups. Incremental AUC₇ of D3 and 25(OH)D3 in D3-treated groups and D2 and 25(OH)D2 in D2-treated groups were higher in females than males (55, 13, 64, and 28%, respectively). Baseline 25(OH)D level predicted response to D2 and D3 (p < 0.001), whereas, BMI was significant predictor only for early response to D2.

CONCLUSIONS

Effects of D2 and D3 supplements on 25 (OH)D level may be dosing-schedule and sex-dependent. D2-associated reduction in 25(OH)D3 level may be related to total 25(OH)D level rather than being D2-specific. D2 may be 25-hydroxylated faster than D3.

TRIAL REGISTRATION

ClinicalTrial.gov identifier: NCT01170494 (registered July 25, 2010).

Food-based solutions for vitamin D deficiency: putting policy into practice and the key role for research

Recent re-evaluations of dietary reference values (DRV) for vitamin D have established intake requirements between 10 and 20 µg/d. National nutrition surveys indicate that habitual mean intakes of vitamin D in the population are typically in the range 3-7 µg/d. As vitamin D supplementation will not be effective at a population level because the uptake is generally low, creative food-based solutions are needed to bridge the gap between current intakes and these new requirement values. The overarching aim of this review is to highlight how food-based solutions can have an important role in bridging this gap and counteracting vitamin D inadequacy in Europe and elsewhere. The present review initially briefly overviews very recent new European DRV for vitamin D and, while not in agreement on requirement estimates, how they point very clearly to the need for food-based solutions. The review discusses the need for traditional fortification of foods in the dairy and other sectors, and finally overviews recent advances in the area of biofortification of food with vitamin D. In conclusion, increasing vitamin D intakes across the population distribution is important from a public health perspective to reduce the high degree of inadequacy of vitamin D intake in Europe. Fortification, including biofortification, of a wider range of foods, which accommodate diversity, is likely to have the potential to increase vitamin D intakes across the population distribution. Research has had, and will continue to have, a key role in terms of developing food-based solutions and tackling vitamin D deficiency.

Impact on Vitamin D2, Vitamin D4 and Agaritine in Agaricus bisporus Mushrooms after Artificial and Natural Solar UV Light Exposure

Commercial mushroom production can expose mushrooms post-harvest to UV light for purposes of vitamin D2 enrichment by converting the naturally occurring provitamin D2 (ergosterol). The objectives of the present study were to artificially simulate solar UV-B doses occurring naturally in Central Europe and to investigate vitamin D2 and vitamin D4 production in sliced Agaricus bisporus (button mushrooms) and to analyse and compare the agaritine content of naturally and artificially UV-irradiated mushrooms. Agaritine was measured for safety aspects even though there is no rationale for a link between UV light exposure and agaritine content. The artificial UV-B dose of 0.53 J/cm(2) raised the vitamin D2 content to significantly (P < 0.001) higher levels of 67.1 ± 9.9 μg/g dry weight (DW) than sun exposure (3.9 ± 0.8 μg/g dry DW). We observed a positive correlation between vitamin D4 and vitamin D2 production (r(2) = 0.96, P < 0.001) after artificial UV irradiation, with vitamin D4 levels ranging from 0 to 20.9 μg/g DW. The agaritine content varied widely but remained within normal ranges in all samples. Irrespective of the irradiation source, agaritine dropped dramatically in conjunction with all UV-B doses both artificial and natural solar, probably due to its known instability. The biological action of vitamin D from UV-exposed mushrooms reflects the activity of these two major vitamin D analogues (D2, D4). Vitamin D4 should be analysed and agaritine disregarded in future studies of UV-exposed mushrooms.