Naturally enhanced eggs as a source of vitamin D: A review
Line Lundbæk Barnkob Trends in Food Science & Technology Volume 102, August 2020, Pages 62-70
Highlights
• Three methods to produce eggs naturally enhanced with vitamin D was reviewed.
• There is a linear inter-trial relationship between vitamin D3 in feed and vitamin D3 content in egg.
• Feed is superior to UVB irradiation in regards to vitamin D enhancement in eggs.
• Egg yolk can be vitamin D enhanced by direct exposure to UVB radiation.
• Naturally enhanced eggs can contribute to increased vitamin D intake in the general population.
Background
It is estimated that on annual basis 40% of the European population is either vitamin D insufficient/deficient. A way to increase the vitamin D intake is to fortify a broader range of foods or by increasing the natural vitamin D content in food sources that already contain vitamin D. Eggs is once again considered part of a healthy varied diet and eggs contain a wide range of micro nutrients including vitamin D.
Scope and approach
Review of production methods to naturally enhance eggs with vitamin D, and discussion of the perspectives of vitamin D enhanced eggs as part of the strategy to increase the dietary intake of vitamin D.
Key findings and conclusions
There are three ways to naturally enhance the vitamin D content in eggs:
feeding more vitamin D3/25(OH)D3 to the hens,
exposing the hens to UVB and
exposing liquid egg products to UVB.
Naturally enhanced eggs can contribute to increased vitamin D intake. An inter-trial linear relationship between vitamin D3 in feed and vitamin D3 in eggs was found. Within the linear range a maximum of 20 μg/100 g yolk was obtained with feed contain 617.5 μg/kg feed. Feed can provide higher levels of vitamin D in eggs than UVB exposure of the hens. However, the European maximum for vitamin D in feed for layers at 80 μg/kg limits the beneficial effect. Vitamin D content in liquid egg products can be tailored by adjusting the UVB dose, however further research is needed.
