Type 1 disease less prevalent in populations living nearer equator, study finds
Adequate sun exposure and vitamin D levels may play an important role in helping to prevent type 1 diabetes in children, a new study suggests.
Researchers at the University of California, San Diego, analyzed type 1 diabetes incidence rates and found that populations living at or near the equator — where there is abundant sunshine — have lower rates of the disease than populations at higher latitudes, where there is less sunlight.
Sunlight exposure causes the skin to produce vitamin D, which is also available through food and supplements.
“This is the first study, to our knowledge, to show that higher serum levels of vitamin D are associated with reduced incidence rates of type 1 diabetes worldwide,” Cedric F. Garland, professor of family and preventive medicine, said in a prepared statement.
“The research suggests that childhood type 1 diabetes may be preventable with a modest intake of vitamin D3 (1,000 IU/day), ideally with five to 10 minutes of sunlight around noontime, when good weather allows,” Garland said.
“Infants less than a year old should not be given more than 400 IU per day without consulting a doctor. Hats and dark glasses are a good idea to wear when in the sun at any age, and can be used if the child will tolerate them,” he advised.
The study was published online Thursday in the journal Diabetologia.
Garland and his colleagues called for public health action to reduce widespread vitamin D inadequacy in U.S. children.
“This study presents strong epidemiological evidence to suggest that we may be able to prevent new cases of type 1 diabetes. By preventing this disease, we would prevent its many devastating consequences,” Garland said.
Type 1 diabetes is the second most common chronic childhood disease, behind asthma. About 1.5 million Americans have type 1 diabetes, and about 15,000 new cases are diagnosed each year. The disease is the main cause of blindness in young and middle-aged adults and is among the leading causes of kidney failure and transplants in that age group, according to a news release about the study.