Children and teenagers with type 1 diabetes may have a particularly high rate of deficiency in bone-building vitamin D, a small study suggests.

The findings, say researchers, underscore the importance of adequate vitamin D intake for children with type 1 diabetes - who, studies suggest, are already at particular risk for bone loss as they grow older.

Among 128 children and teens with the disease, three-quarters had inadequate levels of vitamin D in their blood. Sixty-one percent had insufficient levels of the vitamin, while 15 percent had an outright deficiency.

“To our surprise, we found extremely high rates of vitamin D inadequacy,” senior researcher Dr. Lori Laffel, of Harvard Medical School in Boston, said in a written statement. “We didn’t expect to find that only 24 percent of the study population would have adequate levels.”

Writing in the Journal of Pediatrics, the investigators say the findings suggest that low vitamin D levels may be a particular problem for children with type 1 diabetes.

Other studies have found that the condition itself may put people at risk of greater bone-density loss over time. High blood sugar levels, too much calcium loss through the urine, and chronic inflammation in the body may all play a role in this.

Because those problems are inherent with type 1 diabetes, it is important to focus on the bone-health factors that can more easily be changed, according to Laffel and her colleagues. That includes vitamin D intake.

The American Academy of Pediatrics recommends that children and teenagers get 400 International Units of vitamin D each day. Milk and breakfast cereals fortified with vitamin D are among the main food sources; few foods naturally contain the vitamin, though some fish - like salmon, mackerel and tuna - contain substantial amounts.

Children with diabetes who do not get enough vitamin-D-rich foods should take 400 IU per day through supplements, Laffel and her colleagues advise.

SOURCE: Journal of Pediatrics, January 2009.