Vitamin D metabolites in bovine milk and butter

Comparative bioavailability of vitamins in human foods sourced from animals and plants

Vitamins are essential components of enzyme systems involved in normal growth and function. The quantitative estimation of the proportion of dietary vitamins, that is in a form available for utilization by the human body, is limited and fragmentary. This review provides the current state of knowledge on the bioavailability of thirteen vitamins and choline, to evaluate whether there are differences in vitamin bioavailability when human foods are sourced from animals or plants. The bioavailability of naturally occurring choline, vitamin D, vitamin E, and vitamin K in food awaits further studies. Animal-sourced foods are the almost exclusive natural sources of dietary vitamin B-12 (65% bioavailable) and preformed vitamin A retinol (74% bioavailable), and contain highly bioavailable biotin (89%), folate (67%), niacin (67%), pantothenic acid (80%), riboflavin (61%), thiamin (82%), and vitamin B-6 (83%). Plant-based foods are the main natural sources of vitamin C (76% bioavailable), provitamin A carotenoid β-carotene (15.6% bioavailable), riboflavin (65% bioavailable), thiamin (81% bioavailable), and vitamin K (16.5% bioavailable). The overview of studies showed that in general, vitamins in foods originating from animals are more bioavailable than vitamins in foods sourced from plants.

Organic Food in Athletes Diet-Narrative Review of Alternative Products in Sports Nutrition

Athletes are characterized by special nutritional needs. Meeting their dietary needs associated with intensive exercise is a prerequisite for effective training and success in sports competitions. Hence, it is important to supply key performance nutrients, such as macronutrients, antioxidants, calcium, vitamin D, or iron, in adequate quantities. The increased need for these nutrients makes it necessary to look for food products on the market that more fully cover these needs. Such products may include organic foods. According to research, they have unique properties and are richer in selected nutrients, such as antioxidants. Hence, the aim of this review was to analyze the available literature as to whether organic foods have the potential to more fully cover the increased nutritional requirements of athletes for selected nutrients compared to conventionally produced foods. A narrative review of current literature was carried out. As the analysis showed, organic foods are characterized by a higher content of antioxidant bioactive compounds, a higher content of n-3 fatty acids, a better n:3/n:6 ratio, and a more optimal amino acid composition, which may result in an appropriate dietary ration design for athletes. In conclusion, organic food appears to be an interesting alternative to meet the special nutritional needs of professional and amateur athletes.

Scientific opinion on the tolerable upper intake level for vitamin D, including the derivation of a conversion factor for calcidiol monohydrate

Following two requests from the European Commission (EC), the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the revision of the tolerable upper intake level (UL) for vitamin D and to propose a conversion factor (CF) for calcidiol monohydrate into vitamin D3 for labelling purposes. Vitamin D refers to ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), and calcidiol monohydrate. Systematic reviews of the literature were conducted to assess the relative bioavailability of calcidiol monohydrate versus vitamin D3 on serum 25(OH)D concentrations, and for priority adverse health effects of excess vitamin D intake, namely persistent hypercalcaemia/hypercalciuria and endpoints related to musculoskeletal health (i.e. falls, bone fractures, bone mass/density and indices thereof). Based on the available evidence, the Panel proposes a CF for calcidiol monohydrates of 2.5 for labelling purposes. Persistent hypercalciuria, which may be an earlier sign of excess vitamin D than persistent hypercalcaemia, is selected as the critical endpoint on which to base the UL for vitamin D. A lowest-observed-adverse-effect-level (LOAEL) of 250 μg/day is identified from two randomised controlled trials in humans, to which an uncertainty factor of 2.5 is applied to account for the absence of a no-observed-adverse-effect-level (NOAEL). A UL of 100 μg vitamin D equivalents (VDE)/day is established for adults (including pregnant and lactating women) and for adolescents aged 11-17 years, as there is no reason to believe that adolescents in the phase of rapid bone formation and growth have a lower tolerance for vitamin D compared to adults. For children aged 1-10 years, a UL of 50 μg VDE/day is established by considering their smaller body size. Based on available intake data, European populations are unlikely to exceed the UL, except for regular users of food supplements containing high doses of vitamin D.

Recent developments and emerging trends in dietary vitamin D sources and biological conversion

This review elaborates on biochemical characteristics, in vivo metabolism, biological conversion through UV irradiation, as well as dietary fortification of vitamin D. Recent innovations in vitamin D utilization, including nanoencapsulation, direct or indirect addition, emulsion, ultrasound, microwave processing, CRISPR-Cas9 genome editing, as well as UV photoconversion, were summarized. Mushrooms, eggs, yeasts, as well as seafood, such as Barramundi and Atlantic salmon, were typical representatives of original natural food materials for vitamin D bioconversion in relevant research. The critical session thereof referred to the 295 nm UV-B irradiation triggering biological fortification of vitamin D2 and vitamin D3, which occurred in ergosterol from mushrooms, and cholesterol from egg yolk, respectively. The schematic biosynthesis of vitamin D precursors in yeasts regulated miscellaneous enzymes were clearly demonstrated. These summarized pathways played a role as a theoretical primer for vitamin D bioconversion when the UV irradiation technique is concerned. Besides, tomatoes had become the latest potential vitamin D sources after genetic modification. The safety consideration for vitamin D fortified functional food was discussed either. Further research is required to fill the gap of investigating optimized factors like types of eggs, meat, and grain, boarder range of wavelength, and dosage in UV irradiation. Vitamin D has a great potential market in the field of functional food development.

Vitamin D Deficiency in Farm Animals: A Review

One of the most effective vitamins in the musculoskeletal structure and immune system of farm animals is Vitamin D. The widespread risk of Vitamin D deficiency states is known widely resulting in autoimmune diseases, diabetes, rickets, metabolic bone diseases, and cancers. The aim of this review is to address the subject of Vitamin D deficiency in farm animals and the role of vitamin D in health and deficiency states. Although Vitamin D deficiency is generally defined as < 20 ng/mL in serum, but this level remains to be discussed. Vitamin D synthesis in the skin is the major source of Vitamin D in the body and is influenced by genetic and several environmental factors, such as length of sun exposure, season, and latitude. Sun exposure might be limited during winter in some areas, such as northern latitudes. Thus, food sources can play essential roles in supplying the demand for vitamin D. Some animal species have more sensitivity to Vitamin D deficiency due to their different metabolism, homeostasis, and adaptation to specific diets and environments. Farm animal species, such as cattle, pigs, llamas, Alpacas, small ruminants, and broiler chickens are more sensitive to Vitamin D deficiency. However, some farm animal species including horses and donkeys usually have a low risk of Vitamin D deficiency. Therefore, the management of Vitamin D deficiency and its consequences are critical in some species. The inclusion of Vitamin D in the body of farm animals depended on farming practices, sun exposure in different seasons, and the content of diets. Due to the diversity of species, regulation of many ongoing processes in animals’ bodies, the complexity of Vitamin D metabolism, and different metabolites, more studies are necessary to find the vital roles of vitamin D in the prevention and control of diseases in farm animals.

A “Good Life” for Dairy Cattle: Developing and Piloting a Framework for Assessing Positive Welfare Opportunities Based on Scientific Evidence and Farmer Expertise

Simple Summary

There is increasing appetite to understand how we can provide quality of life to farm animals. A framework to evaluate positive welfare opportunities for dairy cattle was developed using a participatory approach where farmer’s recommendations were integrated into a scientific framework and piloted on farm by vets. When provided with the opportunity to collaborate, farmers and scientists broadly agree on what constitutes “a good life” for dairy cattle and worked together to develop an assessment framework. Farmers did not agree equally on the value of each positive welfare opportunity. However, farmers supported positive welfare assessment as a means of recognition and reward for higher animal welfare, within existing farm assurance schemes, and to justify national and global marketing claims of higher animal welfare.

Abstract

On-farm welfare assessment tends to focus on minimising negative welfare, but providing positive welfare is important in order to give animals a good life. This study developed a positive welfare framework for dairy cows based on the existing scientific literature which has focused on developing positive welfare indicators, and trialled a participatory approach with farmers; refining the framework based on their recommendations, followed by a vet pilot phase on farm. The results revealed that farmers and scientists agree on what constitutes “a good life” for dairy cattle. Farmers value positive welfare because they value their cows’ quality of life, and want to be proud of their work, improve their own wellbeing as well as receive business benefits. For each good life resource, the proportion of farmers going above and beyond legislation ranged from 27 to 84%. Furthermore, barriers to achieving positive welfare opportunities, including monetary and time costs, were not apparently insurmountable if implementation costs were remunerated (by the government). However, the intrinsic value in providing such opportunities also incentivises farmers. Overall, most farmers appeared to support positive welfare assessment, with the largest proportion (50%) supporting its use within existing farm assurance schemes, or to justify national and global marketing claims. Collaborating with farmers to co-create policy is crucial to showcase and quantify the UK’s high welfare standards, and to maximise engagement, relevance and uptake of animal welfare policy, to ensure continuous improvement and leadership in the quality of lives for farm animals.

Rapid Determination of Vitamin D3 in Aquatic Products by Polypyrrole-Coated Magnetic Nanoparticles Extraction Coupled with High-Performance Liquid Chromatography Detection

A method using polypyrrole-coated Fe3O4 (Fe3O4@PPy composites) based extraction coupled with high performance liquid chromatography was developed for adsorption and detection of trace vitamin D3 (VD3) in aquatic products. The fabricated Fe3O4@PPy composites were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Fe3O4@PPy composites showed efficient adsorption of VD3 at pH 9.0 and 25 °C with a dose of 25 mg per 10 mL of sample solution and an adsorption time of 11 min. Methanol was selected as the desorption solvent to recover VD3 from Fe3O4@PPy composites after 3 min of static treatment. Fe3O4@PPy composites can be used for VD3 adsorption at least two times. The developed method showed a good linearity for VD3 determination in the range of 0.1-10 μg/mL with a correlation coefficient of 0.9989. The limits of detection and quantification were 10 ng/mL and 33 ng/mL, respectively. The recovery of VD3 in a spiking test was 97.72% with a relative standard deviation value of 1.78%. The content of VD3 in nine aquatic products was determined with this method. Our results show that Fe3O4@PPy composites provide a convenient method for the adsorption and determination of VD3 from the complex matrix of aquatic products.

Lipid-soluble vitamins from dairy products: Extraction, purification, and analytical techniques

Milk and dairy products are considered as essential sources of lipid-soluble vitamins (LSVs) for human nutrition. Due to the lower concentrations, complexity, and instability of LSVs during extraction, their quantification remains challenging. This review focus on advances in the extraction and quantification of LSVs from different dairy products. Saponification, and liquid-liquid (LLE), solid-phase (SPE), and supercritical fluid (SFE) extraction methods, as well as dispersive liquid-liquid microextraction, are the most common techniques. Liquid chromatography-mass spectrophotometry (LC-MS) has unique advantages for LSVs determination and quantification due to its high sensitivity and specificity.

Detection of Vitamin D Metabolites in Breast Milk: Perspectives and challenges for measurement by Liquid Chromatography Tandem-Mass Spectrometry

Breast milk is an emerging matrix for vitamin D assessment of breastfed infants and their mothers. It is considered a more reliable indicator of infant intake than the assessment of maternal circulating vitamin D. With the improved sensitivity of mass spectrometry-based technologies, this method principle has been the recent mainstay for the quantitation of various vitamin D metabolites in breast milk for population-based clinical trials. There are still several areas across the total testing process (pre-analytical, analytical and post-analytical) to be defined and harmonised to translate breast milk vitamin D measurement by liquid chromatography-tandem mass spectrometry (LC-MS/MS) from population-based research to routine clinical use and public health applications. Pre-analytically, the determination of the best form of vitamin D to measure in breast milk requires more evidence. Analytically, standardisation of the methods to allow for comparability of results is required. Post analytically, breast milk vitamin D decision limits are needed to turn the individual numerical outputs into clinically meaningful results. This review aims to synthesise the current evidence and utility of measurement of breast milk vitamin D by LC-MS/MS and to lead a future discussion on best practices to allow for its clinical utility beyond its current research-based use.

Safety of calcidiol monohydrate produced by chemical synthesis as a novel food pursuant to Regulation (EU) 2015/2283

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 the safety of calcidiol monohydrate as a novel food (NF) pursuant to Regulation (EU) 2015/2283, including its bioavailability as a metabolite of vitamin D3 when added for nutritional purposes to food supplements. The NF is produced chemically. It is proposed in food supplements up to 10 μg/day for individuals ≥ 11 years of age, including pregnant and lactating women and up to 5 μg/day in 3- to 10-year-old children. The production process, composition, specifications and stability of the NF do not raise safety concerns. Animal and human data indicate efficient absorption. The NF contains a fraction of nanoparticles, which are fat soluble and unlikely to reach systemic distribution. There are no concerns regarding genotoxicity. Human adult studies do not raise safety concerns. Combined intake estimates of calcidiol from the NF and calcidiol and vitamin D from the diet were below the tolerable upper intake level (UL) for vitamin D for subjects above 11 years of age. The achieved mean serum 25(OH)D concentration in adults supplemented with 10 μg NF per day remained below 200 nmol/L. The Panel concludes that the NF is safe under the proposed conditions of use and use levels for individuals ≥ 11 years old, including pregnant and lactating women. The applicant did not provide data on the bioavailability and safety of the NF in children. The combined intake estimation in children (3-10 years) is close to the UL for vitamin D. Therefore, the Panel could not conclude on the safety of consumption of the NF in children (3-10 years) at the proposed daily intake. The NF is a bioavailable source of the biologically active metabolite of vitamin D, i.e. 1,25-dihydroxyvitamin D.

Vitamin D composition of Australian foods

Australia needs accurate vitamin D food composition data to support public health initiatives. Previously, limitations in analytical methodology have precluded development of a comprehensive database. We used liquid chromatography with triple quadrupole mass spectrometry (LC-QQQ) to analyse 149 composite samples representing 98 foods (primary samples n = 896) in duplicate for vitamin D₃, 25-hydroxyvitamin D₃ (25(OH)D₃), vitamin D₂, 25(OH)D₂. The greatest concentrations of vitamin D₃ were found in canned salmon and a malted chocolate drink powder (fortified); chicken eggs and chicken leg meat contained the most 25(OH)D₃. Margarine (fortified) and chocolate contained the greatest concentrations of vitamin D₂, with smaller amounts found in various meat products. 25(OH)D₂ was detected in various foods, including meats, and was quantitated in lamb liver. These data advance knowledge of dietary vitamin D in Australia and highlight the importance of analysis of these four forms of vitamin D to accurately represent the vitamin D content of food.

Quantification of vitamin D3 and 25-hydroxyvitamin D3 in food - The impact of eluent additives and labelled internal standards on matrix effects in LC-MS/MS analysis

Deuterated vitamin D standards are used commonly as internal standards in LC-MS/MS analysis of vitamin D3 and 25-hydroxyvitamin D3 in food. However, the use of various eluent additives, such as methylamine, formic acid and ammonium formate, also contributes to matrix effects and the performance of analysis by affecting accuracy and robustness. For the first time, continuous post-column infusion experiments of isotopically labelled vitamin D3-[d6] were performed to evaluate ion-suppression in a wide variety of food (salmon, cheese, pork fat, pork meat, and egg yolk). Furthermore, results collected using five analytical methods, employing DAD/UV and MS/MS-detectors, were evaluated with in-house and standardised reference materials. The matrix effect was significant when analysing vitamin D3 in most food matrices using the deuterium labelled internal standard. Even though the use of the 13C5-labelled internal standard reduced matrix effects, a standardised method is needed to agree on the true value of vitamin D in food.

Vitamin-related phenotypic adaptation to exposomal factors: The folate-vitamin D-exposome triad

The biological role of two key vitamins, folic acid and vitamin D is so fundamental to life processes, it follows that their UV sensitivity, dietary abundance (both key exposomal factors) and variability in dependent genes will modify their functional efficacy, particularly in the context of maintaining the integrity and function of genome and epigenome. This article therefore examines folate and vitamin D-related phenotypic adaptation to environmental factors which vary across the human life cycle as well as over an evolutionary time-scale. Molecular mechanisms, key nutrigenomic factors, phenotypic maladaptation and evolutionary models are discussed.

Natural Vitamin D in Food: To What Degree Does 25-Hydroxyvitamin D Contribute to the Vitamin D Activity in Food?

Vitamin D3, vitamin D2, 25-hydroxyvitamin D3 [25(OH)D₃], and 25-hydroxyvitamin D2 [25(OH)D₂]constitute the vitamin D activity in food. In general, vitamin D activity in food depends on the food's fat content, the feed the animals have been fed, and the animal's exposure to ultraviolet B (UVB) light. There are many gaps in our knowledge of 25-hydroxyvitamin D in food, including the amount present in different types of food, and the amount we process in our daily dietary intake. We aimed to assess the vitamin D vitamers in food (eggs, milk, dairy products, chicken, veal, beef, and pork) on the Danish market using accredited analytical methods. We then combined these data with existing Danish data, as well as with the information from the Danish Dietary Survey to estimate the dietary intake of vitamin D3 and of 25(OH)D₃ by Danes. We report the level of vitamin D in 10% minced pork from free-range pigs slaughtered in summer as 1.39 μg vitamin D3/100 g and 0.40 μg 25(OH)D₃/100 g, which are significantly higher amounts (p < 0.001) than in early spring. The levels of vitamin D2 and 25(OH)D₂ are usually <0.05 μg/100 g, though in beef they are up to 0.14 μg/100 g. 25(OH)D₃ accounts for up to 100% in veal and 8% in fat from free-range pigs. In the Danish diet, the share of 25(OH)D₃ is 24% for children (4-17 years) and 18% for adults (18-75 years). Changes in animal-feeding strategy in the agriculture sector could change the share of 25(OH)D₃ to 11% and 12% if extra vitamin D3 is added to the feed, and the animals are exposed to sunlight or UVB lightlight. Replacing vitamin D3 by 25(OH)D₃ in the feed may result in a share of 25(OH)D₃ of 52% and 40%, respectively, in children and adults. These estimates are based on the assumption that vitamin D3 and 25(OH)D₃ contribute equally to the vitamin D activity. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Vitamin D3 content of cows' milk produced in Northern Ireland and its efficacy as a vehicle for vitamin D fortification: a UK model

Cows' milk is a relatively poor source of vitamin D but figures listed in UK food composition tables may be outdated. Samples of milk were collected for 1-year and vitamin D₃ concentrations analysed using HPLC. Milk consumption data were obtained from the National Diet and Nutrition Survey (Years 1-4). A theoretical model applied vitamin D₃ fortifications of 1 μg, 1.5 μg and 2 μg/100g to simulate improvements in vitamin D intakes. Mean ± SD vitamin D₃ in whole milk was 0.06 ± 0.02 μg/100g. No seasonal differences were apparent. Fortification of cows' milks with 1 μg, 1.5 μg and 2.0 μg/100g, theoretically increased median vitamin D intakes from 2.0 μg/day to 4.2 μg, 5.1 μg and 5.9 μg/day, respectively. Higher vitamin D₃ in milk from this study than that currently in food composition tables, suggests further analysis is warranted. This model suggests vitamin D fortification of cows' milk is an effective strategy to help more of the population achieve recently revised RNIs for vitamin D.

Vitamin D3 in High-Quality Cow Milk: An Italian Case Study

The quality-labeling category of high-quality (HQ) milk defined by the Italian legislation must comply with specific requirements concerning rigorous breeder management, hygienic controls, fat and protein content, bacterial load, somatic cells, lactic acid content, and non-denatured soluble serum proteins. However, there is no specification for the vitamin D content of HQ milk. Moreover, the data on the vitamin D content of this milk category are very scarce. In the present study, the content of vitamin D3 was evaluated in HQ raw and pasteurized cow milk obtained from Italian cowsheds and supermarkets. The vitamin D3 content varied from not detected (less than 1 µg L-1) to 17.0 ± 2.0 µg L-1 milk and was not related to the milk fat content. These results represent a case study including a significant although not exhaustive part of the contemporary Italian market of HQ milk. It was shown for the first time that HQ raw milk does not necessarily contain more vitamin D3, even though non-expert consumers likely to buy milk labeled as HQ could expect it. The vitamin D3 content in HQ pasteurized whole milk should be reported on the label of the milk package as a best practice of consumer information policy.

Consensus statement from 2nd International Conference on Controversies in Vitamin D

The 2nd International Conference on Controversies in Vitamin D was held in Monteriggioni (Siena), Italy, September 11-14, 2018. The aim of this meeting was to address ongoing controversies and timely topics in vitamin D research, to review available data related to these topics and controversies, to promote discussion to help resolve lingering issues and ultimately to suggest a research agenda to clarify areas of uncertainty. Several issues from the first conference, held in 2017, were revisited, such as assays used to determine serum 25-hydroxyvitamin D [25(OH)D] concentration, which remains a critical and controversial issue for defining vitamin D status. Definitions of vitamin D nutritional status (i.e. sufficiency, insufficiency and deficiency) were also revisited. New areas were reviewed, including vitamin D threshold values and how they should be defined in the context of specific diseases, sources of vitamin D and risk factors associated with vitamin D deficiency. Non-skeletal aspects related to vitamin D were also discussed, including the reproductive system, neurology, chronic kidney disease and falls. The therapeutic role of vitamin D and findings from recent clinical trials were also addressed. The topics were considered by 3 focus groups and divided into three main areas: 1) "Laboratory": assays and threshold values to define vitamin D status; 2) "Clinical": sources of vitamin D and risk factors and role of vitamin D in non-skeletal disease and 3) "Therapeutics": controversial issues on observational studies and recent randomized controlled trials. In this report, we present a summary of our findings.

Determination of cholecalciferol (vitamin D3) in bovine milk by dispersive micro-solid phase extraction based on the magnetic three-dimensional graphene-sporopollenin sorbent

In this research, a new magnetic sorbent material composed of three-dimensional graphene aerogel decorated with Fe₃O₄ nanoparticles attached to hollow sporopollenin exine capsules was synthesized and applied for extraction of vitamin D₃ before HPLC-UV analysis. The adsorbent was characterized by FT-IR, SEM, VSM, and zeta potential techniques. The important parameters of the extraction process, including adsorbent dosage, desorption conditions, adsorption time, pH, and salt concentration, were investigated. Under the optimized condition, the method analytical figures of merit were evaluated as follows: linear dynamic range, 10-500 μg L^-1; limit of detection, 3.01 μg L^-1; determination coefficient (R²), 0.9960; intra-day RSD, 5.28%; and inter-day RSD, 8.17%. The applicability of the method was assessed for the determination of vitamin D3 in different unfortified and fortified bovine milk samples, and the recoveries in the 71.8-113.3% range with the RSDs within 1.4-7.0% were obtained.

Challenges to Quantify Total Vitamin Activity: How to Combine the Contribution of Diverse Vitamers?

This state-of-the-art review aims to highlight the challenges in quantifying vitamin activity in foods that contain several vitamers of a group, using as examples the fat-soluble vitamins A and D as well as the water-soluble folate. The absorption, metabolism, and physiology of these examples are described along with the current analytical methodology, with an emphasis on approaches to standardization. Moreover, the major food sources for the vitamins are numerated. The article focuses particularly on outlining the so-called SLAMENGHI factors influencing a vitamer's' ability to act as a vitamin, that is, molecular species, linkage, amount, matrix, effectors of absorption, nutrition status, genetics, host-related factors, and the interaction of these. After summarizing the current approaches to estimating the total content of each vitamin group, the review concludes by outlining the research gaps and future perspectives in vitamin analysis. There are no standardized methods for the quantification of the vitamers of vitamin A, vitamin D, and folate in foods. For folate and β-carotene, a difference in vitamer activity between foods and supplements has been confirmed, whereas no difference has been observed for vitamin D. For differences in vitamer activity between provitamin A carotenoids and retinol, and between 25-hydroxyvitamin D and vitamin D, international consensus is lacking. The challenges facing each of the specific vitamin communities are the gaps in knowledge about bioaccessibility and bioavailability for each of the various vitamers. The differences between the vitamins make it difficult to formulate a common strategy for assessing the quantitative differences between the vitamers. In the future, optimized stationary digestive models and the more advanced dynamic digestive models combined with in vitro models for bioavailability could more closely resemble in vivo results. New knowledge will enable us to transfer nutrient recommendations into improved dietary advice to increase public health throughout the human life cycle.

Salting-out assisted liquid-liquid extraction coupled with high-performance liquid chromatography for the determination of vitamin D3 in milk samples

In this study, salting-out assisted liquid-liquid extraction (SALLE) as a simple and efficient extraction technique followed by high-performance liquid chromatography (HPLC) was employed for the determination of vitamin D3 in milk samples. The sample treatment is based on the use of water-miscible acetonitrile as the extractant and acetonitrile phase separation under high-salt conditions. Under the optimum conditions, acetonitrile and ammonium sulfate were used as the extraction solvent and salting-out agent, respectively. The vitamin D3 extract was separated using Hypersil ODS (250x i.d 4.6 mm, 5 µm) HPLC column that was coupled with diode array detector. Vitamin D2 was used as internal standard (IS) to offset any variations in chromatographic conditions. The vitamin D3 and the IS were eluted in 18 min. Good linearity (r 2 > 0.99) was obtained within the range of 25-600 ng g-1 with the limit of detection of 15 ng g-1 and limit of quantification of 25 ng g-1. The validated method was applied for the determination of vitamin D3 in milk samples. The recoveries for spiked samples were from 94.4 to 113.5%.

Short communication: Technological and seasonal variations of vitamin D and other nutritional components in donkey milk

Vitamin D is an essential nutrient that plays a crucial role in calcium homeostasis and bone metabolism and also acts as a hormone. Although several studies on the content of vitamin D in bovine milk have been conducted, little information is available regarding donkey milk. In the context of the nutritional assessment of donkey milk, the aim of this study was to assess the vitamin D content in donkey milk and its chemical profile, with particular reference to seasonal and technological modifications after pasteurization. The study was conducted on a dairy farm that produces donkey milk for human consumption located in central Italy. At sampling time, an aliquot of total bulk milk production was sampled before and after pasteurization (63°C for 30 min without homogenization) with a total of 20 raw and 20 pasteurized milk samples. The samples were collected for 10 mo, every 15 d, from May to February 2017. All the samples were analyzed for the chemical composition and vitamin D₂ and D₃ content by HPLC after saponification. The donkey milk analyzed showed a higher average vitamin D content (raw milk: vitamin D₂ = 1.68, vitamin D₃ = 0.60 μg/100 mL; pasteurized milk: vitamin D₂ = 1.38, vitamin D₃ = 0.30 μg/100 mL) than reported for bovine and human milk. The results of the effect of pasteurization on milk did not highlight significant differences in the total content of vitamin D. However, vitamin D₃ has a poor thermal stability, which led to a significant reduction in content in pasteurized milk compared with raw milk. The total vitamin D content of donkey milk did not show significant variations between seasons; however, a higher concentration of vitamin D₃ was found in spring and summer. In conclusion, raw and pasteurized donkey milk showed a high content of vitamin D, which could be useful in meeting the deficiencies of this vitamin in humans. Further investigations are needed to improve the vitamin D content in donkey milk by increasing its endogenous synthesis or its transfer in milk and to clarify other variability factors.

Prevalence of vitamin D insufficiency and evidence for disease prevention in the older population

The prevalence of vitamin D insufficiency, usually assessed by the analysis of circulating 25-hydroxyvitamin D (25[OH])D), is very high in the aging German population. An important factor that reduces endogenous vitamin D synthesis in older persons is physical inactivity or care-dependency that limits the time spent outside. Additionally, it has been suggested that the age-dependent decline in the glomerular filtration rate is associated with a reduced production of bioactive calcitriol. As this phenomenon is not detectable by the assessment of 25(OH)D, it is necessary to analyze the level of parathyroid hormone as a marker of calcitriol function. Because 25(OH)D levels are highly correlated with an active and healthy life style, data from epidemiological studies are not necessarily suitable to elucidate the role of vitamin D in disease prevention. Recently published meta-analyses of randomized controlled trials (RCTs) showed moderate effects of vitamin D supplementation on fracture risk and found that vitamin D was more effective when administered in combination with calcium. The role of vitamin D in the prevention of falls and frailty remains unclear. Much evidence has demonstrated the beneficial effects of vitamin D on respiratory tract infections and asthma, which are very relevant health issues in the older population. To conclude, vitamin D, particularly combined with calcium, has moderately beneficial effects on the skeletal system and is useful for the prevention of respiratory tract infections.

Vitamin D Vitamers Affect Vitamin D Status Differently in Young Healthy Males

Dietary intake of vitamin D includes vitamin D3 (vitD3), 25-hydroxyvitamin D3 (25OH-D3), and vitamin D2 (vitD2). However, the bioactivity of the different species has not been scientifically established. The hypothesis in this study was that vitD3, 25OH-D3, and vitD2 have an equal effect on 25-hydroxyvitamin D in serum (vitamin D status). To test our hypothesis, we performed a randomized, crossover study. Twelve young males consumed 10 µg/day vitD3 during a four-week run-in period, followed by 3 × 6 weeks of 10 µg/day vitD3, 10 µg/day 25OH-D3, and 10 µg/day vitD2. The content of vitD3, vitD2, 25OH-D3, and 25-hydroxyvitamin D2 (25OH-D2) in serum was quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The hypothesis that the three sources of vitamin D affect vitamin D status equally was rejected. Based on the assumption that 1 µg vitD3/day will show an increase in vitamin D status of 1.96 nmol/L, the results showed that 23 µg vitD2 and 6.8 µg 25OH-D3 was similar to 10 µg vitD3. These results demonstrate that further investigations are necessary to determine how to quantify the total vitamin D activity based on chemical quantification of the individual vitamin D metabolites to replace the total vitamin D activity assessed in biological rat models.

Food sources of vitamin D and their association with 25-hydroxyvitamin D status in Dutch older adults

Various populations are at increased risk of developing a low vitamin D status, in particular older adults. Whereas sun exposure is considered the main source of vitamin D, especially during summer, dietary contributions should not be underestimated. This study aims to identify food sources of vitamin D that associate most strongly with serum vitamin D concentration. Data of 595 Dutch adults, aged ≥65 years, were analysed. Vitamin D intake was assessed with a food frequency questionnaire and 25-hydroxyvitamin D (25(OH)D) was determined in serum. Associations of total vitamin D intake and vitamin D intake from specific food groups with serum 25(OH)D status were examined by P-for trend analyses over tertiles of vitamin D intake, prevalence ratios (PRs), and spline regression. The prevalence of vitamin D deficiency was high, with 36% of the participants having a 25(OH)D status <50nmol/L. Participants with adequate 25(OH)D concentrations were more likely to be men and more likely to be younger than participants with vitamin D deficiency. Total median vitamin D intake was 4.3μg/day, of which 4.0μg/day was provided by foods. Butter and margarine were the leading contributors to total vitamin D intake with 1.8μg/day, followed by the intake of fish and shellfish with 0.56μg/day. Participants with higher intakes of butter and margarine were 21% more likely to have a sufficient 25(OH)D status after adjustment for covariates (T1 vs. T3: PR 1.0 vs. 1.21 (95%CI: 1.03-1.42), P-for trend 0.02). None of the other food groups showed a significant association with the probability of having a sufficient 25(OH)D status. This study shows that vitamin D intake was positively associated with total serum 25(OH)D concentration, with butter and margarine being the most important contributors to total vitamin D intake.

Specialized food composition dataset for vitamin D content in foods based on European standards: Application to dietary intake assessment

A review of national nutrition surveys from 2000 to date, demonstrated high prevalence of vitamin D intakes below the EFSA Adequate Intake (AI) (<15μg/d vitamin D) in adults across Europe. Dietary assessment and modelling are required to monitor efficacy and safety of ongoing strategic vitamin D fortification. To support these studies, a specialized vitamin D food composition dataset, based on EuroFIR standards, was compiled. The FoodEXplorer™ tool was used to retrieve well documented analytical data for vitamin D and arrange the data into two datasets - European (8 European countries, 981 data values) and US (1836 data values). Data were classified, using the LanguaL™, FoodEX2 and ODIN classification systems and ranked according to quality criteria. Significant differences in the content, quality of data values, missing data on vitamin D₂ and 25(OH)D₃ and documentation of analytical methods were observed. The dataset is available through the EuroFIR platform.

In Pursuit of Vitamin D in Plants

Vitamin D deficiency is a global concern. Much research has concentrated on the endogenous synthesis of vitamin D in human skin following exposure to ultraviolet-B radiation (UV-B, 280–315 nm). In many regions of the world there is insufficient UV-B radiation during winter months for adequate vitamin D production, and even when there is sufficient UV-B radiation, lifestyles and concerns about the risks of sun exposure may lead to insufficient exposure and to vitamin D deficiency. In these situations, dietary intake of vitamin D from foods or supplements is important for maintaining optimal vitamin D status. Some foods, such as fatty fish and fish liver oils, certain meats, eggs, mushrooms, dairy, and fortified foods, can provide significant amounts of vitamin D when considered cumulatively across the diet. However, little research has focussed on assessing edible plant foods for potential vitamin D content. The biosynthesis of vitamin D in animals, fungi and yeasts is well established; it is less well known that vitamin D is also biosynthesised in plants. Research dates back to the early 1900s, beginning with in vivo experiments showing the anti-rachitic activity of plants consumed by animals with induced rickets, and in vitro experiments using analytical methods with limited sensitivity. The most sensitive, specific and reliable method for measuring vitamin D and its metabolites is by liquid chromatography tandem mass spectrometry (LC-MS/MS). These assays have only recently been customised to allow measurement in foods, including plant materials. This commentary focuses on the current knowledge and research gaps around vitamin D in plants, and the potential of edible plants as an additional source of vitamin D for humans.

Review: welfare of dairy cows in continuously housed and pasture-based production systems

There is increasing interest in the use of continuous housing systems for dairy cows, with various reasons put forward to advocate such systems. However, the welfare of dairy cows is typically perceived to be better within pasture-based systems, although such judgements are often not scientifically based. The aim of this review was to interrogate the existing scientific literature to compare the welfare, including health, of dairy cows in continuously housed and pasture-based systems. Although summarising existing work, knowledge gaps and directions for future research are also identified. The scope of the review is broad, examining relevant topics under three main headings; health, behaviour and physiology. Regarding health, cows on pasture-based systems had lower levels of lameness, hoof pathologies, hock lesions, mastitis, uterine disease and mortality compared with cows on continuously housed systems. Pasture access also had benefits for dairy cow behaviour, in terms of grazing, improved lying/resting times and lower levels of aggression. Moreover, when given the choice between pasture and indoor housing, cows showed an overall preference for pasture, particularly at night. However, the review highlighted the need for a deeper understanding of cow preference and behaviour. Potential areas for concern within pasture-based systems included physiological indicators of more severe negative energy balance, and in some situations, the potential for compromised welfare with exposure to unpredictable weather conditions. In summary, the results from this review highlight that there remain considerable animal welfare benefits from incorporating pasture access into dairy production systems.

Short communication: artificial ultraviolet B light exposure increases vitamin D levels in cow plasma and milk

The number of dairy cows without access to pasture or sunlight is increasing; therefore, the content of vitamin D in dairy products is decreasing. Ultimately, declining vitamin D levels in dairy products will mean that dairy products are a negligible source of natural vitamin D for humans. We tested the ability of a specially designed UVB lamp to enhance the vitamin D3 content in milk from dairy cows housed indoors. This study included 16 cows divided into 4 groups. Each group was exposed daily to artificial UVB light simulating 1, 2, 3, or 4 h of summer sun at 56°N for 24 d, and the group with simulated exposure to 2 h of summer sun daily continued to be monitored for 73 d. We found a significant increase in 25-hydroxyvitamin D3 (25OHD3) levels in plasma as well as vitamin D3 and 25OHD3 levels in milk after daily exposure for 24 d in all treatment groups. Extending daily exposure to artificial UVB light to 73 d did not lead to an increase of vitamin D3 or 25OHD3 level in the milk. In conclusion, the change in production facilities for dairy cows providing cows with no access to pasture and sunlight causes a decrease of vitamin D levels in dairy products. This decrease may be prevented by exposing cows to artificial UVB light in the stable.

Interlaboratory Trial for Measurement of Vitamin D and 25-Hydroxyvitamin D [25(OH)D] in Foods and a Dietary Supplement Using Liquid Chromatography-Mass Spectrometry

Assessment of total vitamin D intake from foods and dietary supplements (DSs) may be incomplete if 25-hydroxyvitamin D [25(OH)D] intake is not included. However, 25(OH)D data for such intake assessments are lacking, no food or DS reference materials (RMs) are available, and comparison of laboratory performance has been needed. The primary goal of this study was to evaluate whether vitamin D3 and 25(OH)D3 concentrations in food and DS materials could be measured with acceptable reproducibility. Five experienced laboratories from the United States and other countries participated, all using liquid chromatography tandem-mass spectrometry but no common analytical protocol; however, various methods were used for determining vitamin D3 in the DS. Five animal-based materials (including three commercially available RMs) and one DS were analyzed. Reproducibility results for the materials were acceptable. Thus, it is possible to obtain consistent results among experienced laboratories for vitamin D3 and 25(OH)D3 in foods and a DS.

Stability of vitamin D in foodstuffs during cooking

We investigated the retention of vitamin D3 and 25-hydroxyvitamin D3 in eggs, vitamin D3 in margarine, and vitamin D3 and vitamin D2 in bread. Our set-up illustrated the cooking methods usually performed in households i.e. boiling, frying in pan and oven, and baking. All experiments were performed three times independently of one another. The retention of vitamin D compounds in eggs and margarine during heat treatment in an oven for 40 min at normal cooking temperature showed retention at 39-45%, while frying resulted in retention at 82-84%. Boiled eggs were found to have a similar level of retention (86-88%). For bread baked, as recommended in the recipe, the retention of vitamin D3 in rye bread at 69% was lower than the retention in wheat bread at 85%. A similar observation was made for vitamin D2, although the retention was slightly higher, 73% and 89%. No difference between retention of vitamin D3 and 25-hydroxyvitamin D3 in eggs was shown. Cooking may cause detrimental loss of vitamin D, but it depends on the actual foodstuffs and the heating process. Further research is needed to optimise cooking procedures to enhance retention of vitamin D. Vitamin D retention should be taken into account in future calculations of dietary intake of vitamin D.

Randomized controlled trial of the effects of vitamin D–fortified milk and bread on serum 25-hydroxyvitamin D concentrations in families in Denmark during winter: the VitmaD study

BACKGROUND

Vitamin D intakes are lower than dietary recommendations in most populations, and thus, a low vitamin D status is widespread, especially during winter.

OBJECTIVE

We investigated the effects of increasing vitamin D intake to the recommended amount by fortification of milk and bread on serum 25-hydroxyvitamin D [25(OH)D] concentrations in families during winter in Denmark.

DESIGN

The study was a randomized controlled trial in 782 children and adults (4-60 y old) recruited as 201 families. Families were randomly assigned to vitamin D-fortified or nonfortified milk and bread for 6 mo starting in September. The milk and bread replaced the participants' usual consumptions of products.

RESULTS

Median (IQR) vitamin D intakes (habitual diet plus fortified products) were 9.4 mg/d (6.5, 12.3 mg/d) and 2.2 mg/d (1.5, 3.0 mg/d) in fortification and control groups, respectively. Geometric mean (IQR) serum 25(OH)D concentrations decreased from 73.1 nmol/L (61.9, 88.5 nmol/L) to 67.6 nmol/L (56.2, 79.4 nmol/L) in the fortification group and from 71.1 nmol/L (61.2, 85.9 nmol/L) to 41.7 nmol/L (29.5, 58.9 nmol/L) in the control group (both P , 0.001). The final 25(OH)D concentration was significantly higher in the fortification group than in the control group (P , 0.001). By the end of the study, ,1% of subjects in the fortification group and 25% of subjects in the control group had 25(OH)D concentrations ,30 nmol/L and 16% and 65% of subjects, respectively, had 25(OH)D concentrations ,50 nmol/L.

CONCLUSION

Vitamin D fortification of milk and bread reduces the decrease in serum 25(OH)D concentrations during winter and ensures 25(OH)D concentrations .50 nmol/L in children and adults in Denmark.

Natural vitamin D content in animal products

Humans derive most vitamin D from the action of sunlight in their skin. However, in view of the current Western lifestyle with most daily activities taking place indoors, sun exposure is often not sufficient for adequate vitamin D production. For this reason, dietary intake is also of great importance. Animal foodstuffs (e.g., fish, meat, offal, egg, dairy) are the main sources for naturally occurring cholecalciferol (vitamin D-3). This paper therefore aims to provide an up-to-date overview of vitamin D-3 content in various animal foods. The focus lies on the natural vitamin D-3 content because there are many countries in which foods are not regularly fortified with vitamin D. The published data show that the highest values of vitamin D are found in fish and especially in fish liver, but offal also provides considerable amounts of vitamin D. The content in muscle meat is generally much lower. Vitamin D concentrations in egg yolks range between the values for meat and offal. If milk and dairy products are not fortified, they are normally low in vitamin D, with the exception of butter because of its high fat content. However, as recommendations for vitamin D intake have recently been increased considerably, it is difficult to cover the requirements solely by foodstuffs.

Vitamin D content of food and its contribution to vitamin D status: a brief overview and Australian focus

There are only a few natural foods that contain nutritionally significant quantities of vitamin D. These include egg yolk, some fatty fish, and in much lower concentrations, meat. The published values of the vitamin D content of food are summarised here and their contribution to dietary vitamin D intake is discussed, with particular reference to Australia. Dietary vitamin D is unlikely to reach the level recommended by the US Institute of Medicine. It is therefore concluded that dietary vitamin D will only be a component of vitamin D supply, with UV exposure and/or oral supplements continuing to be the main sources of vitamin D to maintain adequate status.

Comprehensive profiling of carotenoids and fat-soluble vitamins in milk from different animal species by LC-DAD-MS/MS hyphenation

This paper describes a novel and efficient analytical method to define the profile of fat-soluble micronutrients in milk from different animal species. Overnight cold saponification was optimized as a simultaneous extraction procedure. Analytes were separated by nonaqueous reversed-phase (NARP) chromatography: carotenoids on a C(30) column and fat-soluble vitamins on a tandem C(18) column system. Besides 12 target analytes for which standards are available (all-trans-lutein, all-trans-zeaxanthin, all-trans-β-cryptoxanthin, all-trans-β-carotene, all-trans-retinol, α-tocopherol, γ-tocopherol, δ-tocopherol, ergocalciferol, cholecalciferol, phylloquinone, and menaquinone-4), the DAD-MS combined detection allowed the provisional identification of other carotenoids on the basis of the expected retention times, the absorbance spectra, and the mass spectrometric data. Retinol and α-tocopherol were the most abundant fat-soluble micronutrients and the only ones found in donkey's milk along with γ-tocopherol. Ewe's milk also proved to be a good source of vitamin K vitamers. Bovine milk showed a large variety of carotenoids that were absent in milk samples from other species with the only exception of all-trans-lutein and all-trans-zeaxanthin.

Fat-soluble vitamin (A, D, E, and β-carotene) contents from a Portuguese autochthonous cow breed--Minhota

In Portugal, commercial milk is obtained almost entirely from cows of the Holstein breed. However, other breeds may also show dairy aptitude, and produce milk of good quality. The aim of this study was to investigate the effect of the breed factor in the vitamin contents of milks from Holstein and the autochthonous Portuguese breed Minhota, as well as possible variations due to season. Milk samples were collected from 15 cows of each breed. Milk from Minhota cows showed higher contents of retinol, retinyl palmitate, α-tocopherol, and β-carotene. No differences were verified between breeds regarding vitamin D(3) content, but Holstein cows presented higher amounts of provitamin D(3). Seasonal variations were not observed for milk samples from Holsteins, and only a very small variation was observed for milk samples from Minhota cows, mainly in retinol, α-tocopherol, and provitamin D(3) levels. This study revealed that breed has a pronounced effect on milk fat-soluble vitamins, which is an important observation regarding future genetic selection plans. Also, the increased vitamin amounts found in milk from Minhota cows can be regarded as an important nutritional parameter that can potentiate the economical value of this breed.