Early nutritional exposures may influence the development of autoimmune processes leading to type 1 diabetes. A prospective analysis published in Diabetologia evaluated whether dietary intake of vitamins A, B, C, D, and E is associated with islet autoimmunity and type 1 diabetes in children with increased genetic risk.

The study included 5,674 children enrolled in the Finnish Type 1 Diabetes Prediction and Prevention cohort, born between 1996 and 2004. Dietary intake was assessed using 3-day food records at 3 and 6 months of age and annually from 1 to 6 years. Primary outcomes were islet autoimmunity, defined by repeated positivity for islet cell autoantibodies and at least one diabetes-related biochemical autoantibody or a diagnosis of type 1 diabetes, and a diagnosis of type 1 diabetes.

During 6 years of follow-up, 247 children (4.4%) developed islet autoimmunity and 94 (1.7%) developed type 1 diabetes. After adjustment for total energy intake, sex, human leukocyte antigen genotype, and family history of diabetes, higher intakes of retinol, vitamin C, and vitamin E were associated with a reduced risk of islet autoimmunity. These nutrients were also associated with a lower risk of type 1 diabetes, although statistical significance was lost after correction for multiple testing. The association between retinol intake and islet autoimmunity was not significant when the 3-month age point was excluded. No significant associations were observed for B vitamins, and only a weak inverse association was seen for vitamin D.

These findings link higher early-life intake of vitamin C and vitamin E to a lower risk of islet autoimmunity in genetically susceptible children.