Limits...
Seasonal Changes in Vitamin D-Effective UVB Availability in Europe and Associations with Population Serum 25-Hydroxyvitamin D

View Article: PubMed Central - PubMed

ABSTRACT

Low vitamin D status is common in Europe. The major source of vitamin D in humans is ultraviolet B (UVB)-induced dermal synthesis of cholecalciferol, whereas food sources are believed to play a lesser role. Our objectives were to assess UVB availability (Jm−2) across several European locations ranging from 35° N to 69° N, and compare these UVB data with representative population serum 25-hydroxyvitamin D (25(OH)D) data from Ireland (51–54° N), Iceland (64° N) and Norway (69° N), as exemplars. Vitamin D-effective UVB availability was modelled for nine European countries/regions using a validated UV irradiance model. Standardized serum 25(OH)D data was accessed from the EC-funded ODIN project. The results showed that UVB availability decreased with increasing latitude (from 35° N to 69° N), while all locations exhibited significant seasonal variation in UVB. The UVB data suggested that the duration of vitamin D winters ranged from none (at 35° N) to eight months (at 69° N). The large seasonal fluctuations in serum 25(OH)D in Irish adults was much dampened in Norwegian and Icelandic adults, despite considerably lower UVB availability at these northern latitudes but with much higher vitamin D intakes. In conclusion, increasing the vitamin D intake can ameliorate the impact of low UVB availability on serum 25(OH)D status in Europe.

No MeSH data available.


Mean modeled UVB doses effective for pre-vitamin D3 synthesis (Jm−2) in Germany (47–55° N) on a daily (A) and monthly (B) basis in a typical year (mean of 2003–2012). Dotted line in panel B reflects a threshold of 1000 Jm−2 as a guide to a dose below which dermal synthesis of pre-vitamin D3 is relatively low.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5037520&req=5

nutrients-08-00533-f001: Mean modeled UVB doses effective for pre-vitamin D3 synthesis (Jm−2) in Germany (47–55° N) on a daily (A) and monthly (B) basis in a typical year (mean of 2003–2012). Dotted line in panel B reflects a threshold of 1000 Jm−2 as a guide to a dose below which dermal synthesis of pre-vitamin D3 is relatively low.

Mentions: The modeled vitamin D effective UVB doses (“modeled UVB doses” henceforth) on a daily basis throughout a typical year (mean of 10 years) for Germany, as an exemplar, are shown in Figure 1a. As might be expected, there was significant variation in UVB dose from day to day as the atmosphere (weather) changed, particularly during the summer period when doses where at the highest. For example, in July daily modeled UVB dose ranged from a minimum of 4900 Jm−2 to a maximum of 6400 Jm−2 (data not shown). Using a threshold of 1000 Jm−2 as that below which dermal synthesis of pre-vitamin D3 is relatively low, shows that it was only mid-March before UVB doses exceeded this threshold, increasing during summer months and decreasing to levels below this threshold by the latter part of October. A mean monthly modeled UVB dose (defined as the mean daily dose for the month) was also calculated from the modeled daily doses for each month (Figure 1B), which was a simpler representation of UVB dose fluctuations over the course of a typical year. Presentation of mean monthly modeled UVB doses was adopted for the various countries and regions in the remainder of the analysis. Mean monthly modeled UVB doses in December and January were extremely low (<200 Jm−2).


Seasonal Changes in Vitamin D-Effective UVB Availability in Europe and Associations with Population Serum 25-Hydroxyvitamin D
Mean modeled UVB doses effective for pre-vitamin D3 synthesis (Jm−2) in Germany (47–55° N) on a daily (A) and monthly (B) basis in a typical year (mean of 2003–2012). Dotted line in panel B reflects a threshold of 1000 Jm−2 as a guide to a dose below which dermal synthesis of pre-vitamin D3 is relatively low.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5037520&req=5

nutrients-08-00533-f001: Mean modeled UVB doses effective for pre-vitamin D3 synthesis (Jm−2) in Germany (47–55° N) on a daily (A) and monthly (B) basis in a typical year (mean of 2003–2012). Dotted line in panel B reflects a threshold of 1000 Jm−2 as a guide to a dose below which dermal synthesis of pre-vitamin D3 is relatively low.
Mentions: The modeled vitamin D effective UVB doses (“modeled UVB doses” henceforth) on a daily basis throughout a typical year (mean of 10 years) for Germany, as an exemplar, are shown in Figure 1a. As might be expected, there was significant variation in UVB dose from day to day as the atmosphere (weather) changed, particularly during the summer period when doses where at the highest. For example, in July daily modeled UVB dose ranged from a minimum of 4900 Jm−2 to a maximum of 6400 Jm−2 (data not shown). Using a threshold of 1000 Jm−2 as that below which dermal synthesis of pre-vitamin D3 is relatively low, shows that it was only mid-March before UVB doses exceeded this threshold, increasing during summer months and decreasing to levels below this threshold by the latter part of October. A mean monthly modeled UVB dose (defined as the mean daily dose for the month) was also calculated from the modeled daily doses for each month (Figure 1B), which was a simpler representation of UVB dose fluctuations over the course of a typical year. Presentation of mean monthly modeled UVB doses was adopted for the various countries and regions in the remainder of the analysis. Mean monthly modeled UVB doses in December and January were extremely low (<200 Jm−2).

View Article: PubMed Central - PubMed

ABSTRACT

Low vitamin D status is common in Europe. The major source of vitamin D in humans is ultraviolet B (UVB)-induced dermal synthesis of cholecalciferol, whereas food sources are believed to play a lesser role. Our objectives were to assess UVB availability (Jm&minus;2) across several European locations ranging from 35&deg; N to 69&deg; N, and compare these UVB data with representative population serum 25-hydroxyvitamin D (25(OH)D) data from Ireland (51&ndash;54&deg; N), Iceland (64&deg; N) and Norway (69&deg; N), as exemplars. Vitamin D-effective UVB availability was modelled for nine European countries/regions using a validated UV irradiance model. Standardized serum 25(OH)D data was accessed from the EC-funded ODIN project. The results showed that UVB availability decreased with increasing latitude (from 35&deg; N to 69&deg; N), while all locations exhibited significant seasonal variation in UVB. The UVB data suggested that the duration of vitamin D winters ranged from none (at 35&deg; N) to eight months (at 69&deg; N). The large seasonal fluctuations in serum 25(OH)D in Irish adults was much dampened in Norwegian and Icelandic adults, despite considerably lower UVB availability at these northern latitudes but with much higher vitamin D intakes. In conclusion, increasing the vitamin D intake can ameliorate the impact of low UVB availability on serum 25(OH)D status in Europe.

No MeSH data available.