By George Citroner
Just half an hour of daily sun exposure during a child’s first summer may reduce their risk of multiple sclerosis (MS) relapses, according to new research that also found similar protective benefits from maternal sun exposure during pregnancy.
Pediatric MS, also known as pediatric-onset multiple sclerosis (POMS), refers to multiple sclerosis that is diagnosed in children and adolescents, typically before the age of 18, and accounts for up to 5 percent of all MS cases. The body’s immune system mistakenly attacks the central nervous system, leading to muscle weakness and a wide range of other symptoms.
“Our findings suggest that sun exposure in early childhood may have long-lasting benefits on the progression of childhood-onset MS,” Dr. Gina Chang of The Children’s Hospital of Philadelphia and a member of the American Academy of Neurology said in a statement.
Reduced MS Relapse Risk in Children
The new study, published in Neurology Neuroimmunology & Neuroinflammation, suggests that brief daily sun exposure may benefit children with pediatric-onset multiple sclerosis. The study, conducted across almost 20 pediatric MS clinics in the United States, followed over 300 children and young adults (ages 4–21) diagnosed with childhood-onset MS from 2011 to 2017, with an average follow-up of three years.
Just over 60 percent experienced at least one relapse, defined as new or recurring symptoms lasting a minimum of 24 hours, occurring at least 30 days apart, and not associated with fever or infection.
After adjusting for factors such as tobacco exposure, birth season, type of MS medication, and sun protection practices, the study found a correlation: children who received at least 30 minutes of sun exposure daily during their first summer had a 33 percent lower risk of relapse compared to those with less sun exposure.
Also, at least 30 minutes of sun exposure for participants’ mothers during their second trimester of pregnancy was associated with a 32 percent lower risk of MS relapses in their children.
Sun exposure and UV radiation later in life did not show a significant impact on relapse risk.
“The idea that a mother’s sun exposure during pregnancy could affect her child’s risk of relapse later in life is fascinating,” Dr. Michael Genovese, chief medical adviser at Ascendant New York and a diplomate of the American Board of Psychiatry and Neurology, who was not part of the study, told The Epoch Times. “It raises interesting questions about how early-life environmental factors shape immune health.”
This was an observational study, so it could not establish a cause-and-effect relationship, only that there was an association.
Genovese pointed out a key limitation of the study: its reliance on parental recall of past sun exposure, which he described as “not always the most reliable data.” He called for further research using measurable vitamin D levels and long-term tracking to validate the findings.
The Vitamin D Connection
While a patient’s sun exposure history isn’t a primary determinant in the management of MS, it can offer valuable context—“primarily through its influence on vitamin D levels,” Dr. Achillefs Ntranos, a neurologist and MS specialist at Achilles Neurology in Beverly Hills, California, told The Epoch Times.
“Sunlight helps the body produce vitamin D, also known as ’the sunshine vitamin,’ and research suggests that adequate vitamin D may reduce MS disease activity,” Ntranos said. This means that for patients with low vitamin D levels or those living in areas with limited sunlight, “we might consider vitamin D supplementation as part of an overall management strategy,” he added.
Vitamin D may help reduce MS activity by regulating immune cells that attack myelin (the protective covering of nerves), and also by lessening inflammation in the brain and spinal cord.
Treatment decisions are “multifaceted” and based on a comprehensive evaluation of disease activity, the patient’s medical history, and personal preferences, Ntranos said. “When planning treatment, I routinely check my MS patients’ vitamin D levels and encourage safe sun exposure or supplements as part of their overall care.”
Adding to Evidence Linking Sun to MS Risk
This study adds to the growing research suggesting that sun exposure and vitamin D levels could influence MS prevention and management.
Some studies have shown that people who get more sunlight over their lifetime tend to have a lower risk of developing MS and often a milder disease course if they do develop it. The connection between MS and where people live is “pretty striking,” Genovese said. MS is more common in places farther from the equator, where people get less year-round sunshine, he noted.
Chang noted that future studies should look at how time in the sun at other points before and after MS diagnosis may affect disease course, to better guide sun exposure recommendations for children living with the condition and help design potential clinical trials. For now, experts recommend balancing the benefits and risks of sun exposure and considering vitamin D intake as part of a comprehensive MS care plan.
“Balance is key—too much sun comes with risks, so any recommendations should be made with that in mind,” Genovese said.
