Vitamin D May Cut Risk of Type 1 Diabetes

June 5, 2008 -- There is new evidence that children who get plenty of vitamin D, either from supplements or sun exposure, have a reduced risk of developing type 1 diabetes.

Vitamin D supplementation during infancy was associated with a 29% reduction in type 1 diabetes risk in a recently published research analysis.

And a new study examining type 1 diabetes rates in specific populations confirms that rates are lower in sunny equatorial countries and higher in northern latitude countries that get far less sunlight.

UVB and Type 1 Diabetes

Skin exposure to ultraviolet B (UVB) through sunlight is a major source of vitamin D, and it has long been recognized that type 1 diabetes rates tend to be greater in higher latitude countries where there is little sunlight, like Finland and Sweden, and lower in countries that are close to the equator.

The observation led to the speculation that vitamin D plays a major role in type 1 diabetes risk, longtime vitamin D researcher Cedric F. Garland, DrPH, tells WebMD.

In an effort to test the theory, Garland and colleagues from the Moores Cancer Center at the University of California, San Diego, examined type 1 diabetes rates worldwide in 51 regions while attempting to control for confounding factors such as the level of medical care.

They confirmed that incidence rates were generally highest in high latitude regions, independent of per capita health expenditures.

"One theory is that high levels of health care in (high latitude) Scandinavian countries may explain the higher diagnosis rates," Garland says. "But Cuba also has very good health care, and we saw very low rates there."

In Finland, for example, about 37 out of 100,000 boys under the age of 14 develop type 1 diabetes. In Cuba, the rate is closer to 2 in 100,000.

The study appears in the June 4 online issue of the journal Diabetologia.