In January the sun is recommended to be approximately 130 minutes, when it should be open not less than ten percent of the body surface. In April and July, just ten minutes, but about a quarter of the body must be opened. In October the sun be half an hour. These recommendations are true for the southern temperate latitudes.
This was announced by Spanish scientists who conducted a study to determine the time and duration of sunbathing.
The article was published in the journal Science of the Total Environment.
It is noted that the main criterion for the assessment scientists chose to obtain an optimal dose of vitamin D that is synthesized in human skin under the influence of daylight.
At Northern mid-latitudes in the sun in winter should be longer. Radiation, which is produced at 10:00, enough for 9.7 hours to meet the needs for vitamin D. Under the action of radiation produced in 16:00, you need to be in a period of 5.7 hours. In both cases, must be open a minimum of ten percent of the body.
On the other hand, in spring and summer, about ten minutes of sun exposure starting from 13:00, and around 20 minutes from 15:00 to 17:00, will be sufficient to meet the daily requirement of vitamin D. Open to solar radiation should be at least a quarter of the body surface.
To such conclusions scientists have analyzed the parameters of the solar radiation during one month each season in the period from 2003 to 2010.
It is noted that these findings hold true for people with a third skin type (they have dark hair, grey or hazel eyes, usually dark skin and no freckles), these include most people living in Spain.
At the same time, people with lighter skin because of the risk of burns, you need less to be in the sun. This means that through natural light sources, they are most likely not getting enough vitamin D.
The authors also noted that the development of vitamin D in adults of middle age, which is 66% from that in children. Experts suggest that to compensate for the possible lack of biologically active substances taking dietary supplements.
