Famine from Feast: Linking Vitamin C, Red Blood Cell Fragility, and Diabetes (PROTOCOL 14DK0060)

National Institute Of Diabetes And Digestive And Kidney Diseases

Investigators

Abstract

Study explores effects hyperglycemia on vitamin C physiology in diabetes. Scientific premise is bBased on data indicating that individuals with diabetes have abnormal and inappropriate loss of vitamin C via the urine, described as a renal leak (Ebenuwa I et al., Am J Clin Nutr. 2022 Jul 6). Reduced vitamin C concentrations have also been linked to altered RBC structure and function (reduced deformability), resulting in reduced microvascular perfusion and microvascular diabetic complications. To investigate our hypothesis that hyperglycemia and vitamin C renal leak contribute to reduced plasma vitamin C concentrations in diabetic individuals, we launched a clinical protocol (NCT02107976) in diabetic subjects to test whether real-time changes in glycemia (dynamic hyperglycemia) induce concurrent changes in plasma, RBC and urine vitamin C concentrations, and RBC deformability. Protocol studies were completed March 2025 and currently in the data analysis stage. Findings will allow us to learn whether there are acute or chronic relationships between hyperglycemia, vitamin C concentrations, and RBC deformability. To our knowledge, this is the first study of controlled dynamic hyperglycemia induced by foods in humans with diabetes.