How long does it take to burn in the sun?
The researchers looked at ultraviolet solar irradiance (UVER) between the hours of 12:30 to 1:30 pm, and found that in order to avoid erythema — the scientific word for a sun rash — individuals, on average, should not spend more than 29 minutes in the sun in the summer.
In the winter however, it is okay to stay in the sun for up to 150 minutes.
Dr. María Antonia Serrano, a Spain-based sun expert and lead author of the study explains:
“In Spain, despite being a country with many hours of sunlight, several articles have reported a high percentage of vitamin D deficiency among various strata of the Spanish population. The problem can appear in winter due to low levels of UV radiation and because people cover most of their bodies.”
In January, with roughly 10% of the body exposed, it would take about 130 minutes to receive enough vitamin D for the day. Contrastingly, with about 25% of the body exposed in April and July, it would require 10 minutes of exposure to reach adequate levels, and about 30 minutes in October.
Age also comes into play here, because as we age, the body’s ability to synthesize vitamin D from UV radiation also changes. For example, middle-aged adults only have 66% of the ability children have to synthesize vitamin D from UV radiation.
Getting Enough Vitamin D in the Winter
If you live in a country with cold winters, it may be difficult to attain the recommended daily vitamin D doses.
Since being outside in the cold for over an hour seems unlikely for most people, the researchers suggest that the best thing to do would be to increase your daily intake of vitamin D supplements, or to eat foods high in vitamin D: these may include fatty fish, like tuna, mackerel, and salmon, egg yolks, and fortified dairy products and juices.
These results can help to adopt the right measures to make up for any deficiency, such as informing the medical profession about the utility of increasing vitamin D intake in the diet or through supplements,” Serrano concludes.