Free-range farming: A natural alternative to produce vitamin D-enriched eggs

Kühn, Julia; Schutkowski, Alexandra; Kluge, H.; Hirche, Frank; Stangl, Gabriele I.

doi:10.1016/j.nut.2013.10.002

Cited by 55 publications

(36 citation statements)

References 13 publications

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“…Thus, variation in animal diet and environment can affect vitamin D 3 and 25(OH)D 3 levels in animal-based foods. 21, 40–48 Unfortunately, data on the 25(OH)D 3 content of foods are limited and existing data can vary greatly. 21,49, 50 …”

Section: Discussionmentioning

confidence: 99%

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

Roseland

Patterson

Andrews

et al. 2016

J. Agric. Food Chem.

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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 U.S. 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.

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Section: Discussionmentioning

confidence: 99%

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

Roseland

Patterson

Andrews

et al. 2016

J. Agric. Food Chem.

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“…As revealed by Kühn et al [25], the free-range farming system could be an appropriate method to fortify eggs with vitamin D, provided free-range farming conditions are sufficiently attractive for the hens to range outside.…”

Section: Nutritional Enhancement Of Eggsmentioning

confidence: 99%

Free Range, Organic? Polish Consumers Preferences Regarding Information on Farming System and Nutritional Enhancement of Eggs: A Discrete Choice Based Experiment

Żakowska‐Biemans

Tekień

2017

Sustainability

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Abstract:The main purpose of this study was to determine the structure of consumer preferences regarding information on farming system and nutritional enhancement of eggs to verify if consumers are willing to accept products combing sustainability and nutrition related claims. The data was collected within a CAPI (Computer Assisted Personal Interviews) survey on a representative sample of 935 consumers responsible for food shopping. A discrete choice-based conjoint method was selected in eliciting consumer preferences among different product profiles with varying levels of attributes. A hierarchical cluster analysis was used to identify four distinct clusters that differed significantly in terms of importance attached to production system attributes and socio-demographic profiles. The results of the experiment showed that price and farming system had the most significant mean relative importance in shaping consumers' preferences, while other attributes such as nutrition and health claims, egg size, package size and hen breed were far less important. Free range eggs had the highest relative importance for consumers despite the fact that organic egg production systems are governed by much stricter animal welfare standards. Our segmentation revealed that two of our four clusters may be more easily reached by information on animal welfare related attributes in egg production than the others. The results of our study provide the policy makers and marketing practitioners with insights applicable for communication and pricing strategies for eggs with sustainability claims.

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“…With a daily irradiation for 300 min, vitamin D 3 content was increased to 28.6 μg/100 g of egg yolk dry matter, but did not reach the plateau, whereas the amount of 25OHD 3 was maximal even after irradiation for 60 min [41]. Vitamin D 3 concentration in egg yolk was three-to fourfold higher (p < 0.001) in the hens that were exposed to sunlight under outdoor and indoor/free-range farming than in those kept indoor [42]. The vitamin D 3 concentration in egg yolk in the free-range farming was 14.3 μg/100 g dry matter, in contrast to 3.8 μg/100 g. The vitamin D content in the egg yolk under mixed keeping conditions occupied an intermediate position.…”

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confidence: 90%