Natural Vitamin D Content in Animal Products

Abstract

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 modulates adipose tissue biology: possible consequences for obesity?

“…Only a few foodstuffs contain significant amounts of VD, the main sources being fish liver oils, fatty fish (sardines, herring and mackerel) and egg yolk (2,3) , but small quantities are also found in fortified milk, orange juice, bread and cereals. Alternatively, VD 3 is produced endogenously in the skin after UVB irradiation from the precursor 7-dehydrocholesterol to give pre-VD 3 , which is further isomerised to VD 3 before being released into the circulation (4) . Classical estimates have assigned a majority (70-90 %) of VD supply to dermal synthesis, but a recent paper revised this figure down to just 10-25 % of VD supply (5) and posited that dietary intake of 25-hydroxy-vitamin D (25(OH)D) is a significant contributor to total VD input.…”

“…It can be obtained through animal (VD 3 , cholecalciferol) or plant (VD 2 , ergocalciferol) food sources. Only a few foodstuffs contain significant amounts of VD, the main sources being fish liver oils, fatty fish (sardines, herring and mackerel) and egg yolk (2,3) , but small quantities are also found in fortified milk, orange juice, bread and cereals.…”

“…It can be obtained through animal (VD 3 , cholecalciferol) or plant (VD 2 , ergocalciferol) food sources. Only a few foodstuffs contain significant amounts of VD, the main sources being fish liver oils, fatty fish (sardines, herring and mackerel) and egg yolk (2,3) , but small quantities are also found in fortified milk, orange juice, bread and cereals. Alternatively, VD 3 is produced endogenously in the skin after UVB irradiation from the precursor 7-dehydrocholesterol to give pre-VD 3 , which is further isomerised to VD 3 before being released into the circulation (4) .…”

Vitamine D : sources, métabolisme et mécanismes d’action

“…Un paramètre largement sous-estimé dans le calcul des apports alimentaires en vitamine D est la contribution de la 25-hydroxyvitamine D, naturellement présente dans les aliments. En effet cette dernière n'est jamais prise en compte dans le calcul des apports exogènes de vitamine D. Pourtant ce métabolite est présent en quantité variable mais non né-gligeable dans un grand nombre d'aliments de consommation courante (Ovesen, et al, 2003 ;Schmid, et al, 2013 de cette molécule dans le maintient des taux plasmatiques notamment chez l'Homme n'est pas complètement établi (Ovesen, et al, 2003) et devra faire l'objet d'études approfondies, afin d'en tenir éventuellement compte dans les calculs d'apports vitaminiques. La principale source de vitamine D 3 est la synthèse endogène qui se déroule au niveau de l'épiderme, après une exposition aux rayonnements ultraviolets B (UVB) fournis par l'ensoleillement.…”

Importance of body weight and skin color in determining appropriate vitamin D3 supplement doses for children and adolescents

“…Because of the relationship between sun exposure and skin cancer in those with light skin, public health authorities have been recommending that the general population lower their sun exposure for over 30 y (16). It is possible to obtain vitamin D through diet; however, other than wild fish that eat a certain type of zooplankton, few food sources have ample amounts of vitamin D (17,18). In developed countries, some foods are fortified with low levels of vitamin D. While this fortification seems to have solved the problem of vitamin D deficiency for some individuals, others continue to be vitamin D deficient.…”