Loading...
 
Translate Register Log In Login with facebookLogin and Register

Time in sun (in Spain) to get 4,000 IU of vitamin D: half hour in July , 2 hours in October – Sept 2016

Solar ultraviolet doses and vitamin D in a northern mid-latitude.

Sci Total Environ. 2016 Sep 21;574:744-750. doi: 10.1016/j.scitotenv.2016.09.102. [Epub ahead of print]
Serrano MA1, Cañada J2, Moreno JC3, Gurrea G4.
1Solar Radiation Research Group, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain. mserranj at fis.upv.es.
2Solar Radiation Research Group, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain.
3Solar Radiation Research Group, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain. jcmestev at fis.upv.es.
4Solar Radiation Research Group, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain. gongurys at csa.upv.es.

VitaminDWiki

PDF indicates 25% body exposed in summer and 10% in winter - reasonable
Abstract does not mention 3 times longer time in the sun is needed if

  • darker skin (they had assumed skin type III)
  • elderly (they had assumed 22 year old)
  • wear lots of clothes (they had asumed 25% skin exposure in summer)

See also VitaminDWiki

No – 10 minutes per day of sun-UVB is NOT enough

  • 5-10 minutes provides only 1,000 IU ONLY IF you are near the equator
  • AND young
  •  AND not obese
  •   AND have light skin
  •    AND it is summer
  •     AND it is the middle of the day
  •      AND you have lots of skin exposed to the sun
  •       AND you are lying down
  •        AND you are not wearing sunscreen
  •         AND you have a healthy Liver
  •          AND no clouds and nor air pollution
  •           AND you have good response to sunshine( 4X variation between individuals)

It also has the following study by McKenzie
see wikipage http://www.vitamindwiki.com/tiki-index.php?page_id=1689

Latitudes: 40 Valencia and Beijing, 52 Berlin, 55 Edmonton and Moscow, 61 Alaska

Another study in 2017- not as good, for Equador

Calculation of the Sun exposure time for the synthesis of vitamin D in Urcuquí, Ecuador
 Download the PDF from VitaminDWiki

Publisher wants $42 for the PDF
Also available at DeepDyve

Solar ultraviolet (UV) radiation is one of the most important factors in the development of skin cancer in human, solar erythema and skin aging. Nevertheless, numerous studies have shown the benefits of UV solar radiation in moderate doses, such as the reduction of blood pressure and mental health, treatment of various diseases, and the synthesis of vitamin D in the skin. This paper analyses data from solar ultraviolet erythemal (UVER) irradiance in W/m2 measured in a northern mid-latitude as Valencia (Spain) for the period 2003-2010. To estimate effective solar UV radiation in the production of vitamin D (UVD) we used the relationship proposed by McKenzie et al. (2009). It was obtained for one month for each season the minimum exposure time needed around solar noon and at 9 UTC and 15 UTC (Coordinated Universal Time) to obtain the recommended daily dose of 1000IU. Also, it has been calculated time for erythema induction around solar noon for the same months. The median UVER daily dose during the summer months was 4000J/m2day, and 700J/m2day in winter. With regard to UVD, the median UVD daily dose in summer season was 7700J/m2day, and in winter it was 1000J/m2day. Around noon in January it takes more than two hours of solar exposure to obtain the recommended daily dose of vitamin D, whereas the rest of the year range between 7min on July and 31min on October. For the same months around noon, exposure times to produce erythema were obtained, these being of higher value to the previous. The results show that it is difficult to obtain the recommended vitamin D doses in winter in a northern mid-latitude, as the human body is almost entirely covered in this season.

Copyright © 2016 Elsevier B.V. All rights reserved. PMID: 27664761 DOI: 10.1016/j.scitotenv.2016.09.102

Attached files

ID Name Comment Uploaded Size Downloads
8079 Equador sun time.pdf PDF 2017 admin 08 Jun, 2017 01:08 814.68 Kb 312
See any problem with this page? Report it (FINALLY WORKS)