Here’s Dr. Jonathan Wright, MD speaking about some studies linking Vitamin D supplementation with decreases in Type 1 Diabetes. I was completely unaware of this research until watching this video:
Vitamin D Deficiency – Dr. Jonathan Wright, MD – YouTube
He does make a mistake about the name of the researcher of the Finnish study who he names as Kekkonen, who was actually the prime minister of Finland. But I think he means this study by Hyppönen et al published in November 2001:
Intake of vitamin D and risk of type 1 diabetes: a birth-cohort study [PDF]
In 2008 a meta-analysis was done on the research linking Vitamin D supplementation in infants with reduced risk of Type 1 Diabetes and found:
Meta-analysis of data from the case-control studies showed that the risk of type 1 diabetes was significantly reduced in infants who were supplemented with vitamin D compared to those who were not supplemented (pooled odds ratio 0.71, 95% CI 0.60 to 0.84). The result of the cohort study was in agreement with that of the meta-analysis. There was also some evidence of a dose-response effect, with those using higher amounts of vitamin D being at lower risk of developing type 1 diabetes. Finally, there was a suggestion that the timing of supplementation might also be important for the subsequent development of type 1 diabetes.