Sunlight in infancy affects the appearance of relapse in children with multiple sclerosis

In the study, scientists from the American Academy of Neurology analyzed medical records of 18 clinics of multiple sclerosis (RS) throughout the United States to identify 334 children and young people with RS, who developed in childhood, aged 4 to 21 years. Participants were observed for four years after the appearance of the first symptoms.

To assess the effects of sunlight, the parents or guardians of the participants filled out questionnaires, which indicated how much time they and their biological mother spent in the sun in various periods of their life, what clothes they wore and how often they used sunscreen. Of the entire group, 206 participants survived at least one relapse during the study. Relapses were defined as new or returning symptoms that last at least 24 hours and separated at least 30 days with the last attack of RS, without the presence of fever or infection.

Studies have shown that among the 75 participants who received from 30 minutes to an hour of sunlight daily in the summer in the first year of life, relapse occurred in 34 children (45%). In a group of 182 participants who received less than 30 minutes of sunlight daily in the summer in the first year of life, relapse occurred in 118 children (65%). After accounting for such factors as the effects of tobacco in the first year of life, the season of birth, the type of drugs taken from multiple sclerosis and the use of protection products from the sun, the researchers found that 30 or more minutes of daily in the summer sun in the first year of life are associated with a reduction in the risk of relapse by 33%.

Researchers also analyzed the effect of sunlight on the biological mothers of children. They found that daily stay in the sun for more than 30 minutes during the second trimester of pregnancy is associated with a 32% decrease in the risk of relapse of multiple sclerosis in a child.