An American trial finds a high percentage of vitamin D deficiency in a large population of children with type 1 diabetes.

Researchers at the University of Pennsylvania School of Nursing looked to examine the association of 25-hydroxyvitamin D and blood glucose levels among children and adolescents with type 1 diabetes.

They recruited 197 children and adolescents and collected non-fasting blood samples to measure 25-hydroxyvitamin D and blood glucose levels. 23 per cent of the children were overweight; 13 per cent were obese.

The Department of Health defines low vitamin D status as a plasma concentration of 25-hydroxyvitamin D below 25 nmol/l. The study results did not list a category as low as this but did find that 41 per cent of the participants had levels below 50 nmol/L.

The researchers noted that a high prevalence of 25-hydroxyvitamin D deficiency was observed in the cohort, specifically among healthy weight and Caucasian children who had previously been considered at no or low risk of having low levels of vitamin D.

However, it should be noted that the level at which they defined a deficiency was at a higher level than the definition from the Department of Health.

The study team highlighted the importance of vitamin D screening for all children and adolescents with type 1 diabetes. However, the relationship between low vitamin D levels and HbA1c levels did not reach statistical significance.

Senior author Terri Lipma, PhD, said: “To our knowledge this is the first study that has been adequately-powered to examine the association between 25-hydroxyvitamin D and HbA1c (a measure of diabetes control) in children and adolescents with type 1 diabetes. These data suggest the need for monitoring of vitamin D in all youth with this disorder.”

The findings appear in Diabetes Research and Clinical Practice.