Vitamin D is synthesized in skin only vitamin ultraviolet rays. This is a certainty. But what is the optimal duration of sun exposure to get the recommended doses of vitamin D? Scientists in Spain have issued, Wednesday, March 8th, a study explains the dilemma. Researchers in the “Solar Radiation Research Group” at the University of Valencia have started from the idea that solar radiation (UV) is essential for the synthesis of vitamin D and supporting healthy physically and mentally, but we must not forget that they also contribute the occurrence of sunburn, skin cancer or premature aging of the skin. That is why it is so important to determine the exact duration of exposure to ultraviolet without being adversely affected health. Vitamin D deficiency, a problem even in sunny countries Maria Antonia Serrano, who led the study, said that despite the mild climate, with sunshine, and the population of Spain is experiencing a shortage of vitamin D.
“Although Spain is a country with many hours of daylight, several articles reported a high percentage of those with a vitamin D deficiency, “she said, according to Science Daily. Vitamin D deficiency is associated with an increased risk of many diseases both in children and adults: rickets predisposition to infection behavioral disorders autoimmune diseases depression cardiovascular diseases Alzheimer’s disease osteoporosis. The main natural source of vitamin D is the synthesis of his skin, made from exposure to ultraviolet rays. This ensures that 80-90% of the vitamin D in the body reserves. The rest can be acquired from the diet: vitamin D3 (cholecalciferol) is obtained from fish, eggs, milk, and vitamin D2 (ergocalciferol) is obtained from fungi, yeast. Scientists argue that most people in the northern hemisphere fail to obtain a sufficient intake of vitamin D due to lack of sun exposure, especially during the months with “r” of the year, less sunny. 20 minutes in the sun in July, 150 minutes in January Here’s what the researchers observed in Spain.
They analyzed the sunlight in Valencia, between the hours 12: 30-13: 30 for four months a year, one in each season, in 2003-2010. The results, published in the journal “Science of the Total Environment”, showed that, in July, people with phenotype 3 skin (most common among the population of Spain) must not spend more than 29 minutes in the sun without cream with SPF to avoid sun damage. In January, exposure to the ultraviolet range can be increased to 150 minutes. In order to obtain the recommended daily dose of vitamin D – equivalent to 1,000 IU (international units), the minimum time of sun exposure is as follows: 130 minutes in January (10% of the body exposed to sunlight); 10 minutes in April-June (with 25% of the body covered); 30 minutes in October. ” These calculations were performed on skin phenotype III, but the figures may change if those who have skin lighter or darker ” attracted the attention of Maria Serrano. She wanted to clarify that it is essential to take into account the coverage of skin, depending on the season, but also posture and body shape. Age also plays a role in this equation, elderly synthesizing more difficult vitamin D.
In conclusion, the average length of sun exposure to achieve recommended a daily dose of vitamin D is 10-20 minutes the spring and summer, while in winter it takes almost two hours to reach optimal intake. You know what your skin phenotype? According to the Romanian Society of Dermatology, most Romanians have a light-colored leather (phenotypes II and III). Phenotype II: fair skin, not tan, but burn unprotected exposure conditions of more than 20 minutes. Phenotype III: Medium skin color, eye color closed or open, brown hair, tanning quickly and easily, often with burns. Should avoid exposure during lunch (12: 00-16: 00). In Romania, specialists estimate that the sun allows natural formation of vitamin D in the body only between 15 May and 15 September. Otherwise, the recommended intake is necessary to ensure additional administration of vitamin D3 or D2.