Can the onset of type 1 diabetes be delayed with vitamin D supplementation in children and adolescents?

This study reviewed the effect of high-dose vitamin D₂ (ergocalciferol) supplementation on delaying the onset of type 1 diabetes (T1D) in children and adolescents with newly diagnosed T1D. The authors recommended maintaining a safe and effective high-dose vitamin D₂ concentration of 30-60 ng/mL for delaying the onset of T1D in these patients.

T1D involves the destruction of beta cells of the pancreas. It occurs due to an attack on the body by the immune system. The resulting effect is low insulin levels with persistently high blood glucose. Typically, at the time of diagnosis, around half of the beta cells of the pancreas are affected. The remaining functional beta cells (RFBC) may persist for months to years. This is known as the partial remission (PR) or honeymoon phase of T1D. Prolonging the amount of time spent in PR improves blood glucose control and long-term complications.

Vitamin D₂ (ergocalciferol) is recognized for its anti-inflammatory effects. It can also modify immune responses and protect RFBC. It is safe for use in children. However, further guidance on vitamin D₂ supplementation in newly diagnosed patients, based on hemoglobin A1c (HbA1c; a blood marker of blood glucose control) and insulin-dose adjusted A1c (IDA A1c; a functional marker of PR) changes, is needed.

This study included 36 children and adolescents with newly diagnosed T1D. Serum concentrations of 25-hydroxyvitamin D [25(OH)D] were determined for all patients. Patients with concentrations of less than 30 ng/mL received vitamin D supplementation with either ergocalciferol or calciferol. They received 50,000 IU weekly for 2 months, then every other week for 10 months, or a placebo. Patients with serum concentrations greater than or equal to 30 ng/mL were periodically monitored. Vitamin D supplementation was given if concentrations decreased to below 30 ng/mL. Changes in HbA1c and IDAA1c were measured.

Vitamin D supplementation significantly reduced the rise in HbA1c and IDAA1c compared to placebo. Serum TNF-α (an indicator of inflammation) was significantly reduced with vitamin D supplementation compared to placebo.

There was no case of vitamin D toxicity, a rise in calcium levels in the blood or in the urine.

This study showed that high-dose vitamin D supplementation with a maintenance target of 30-60 ng/mL for at least 1 year may be beneficial during the PR of T1D in children and adolescents.

This study included a small number of patients. Further studies on very young children are also needed.