Higher doses of ascorbic acid may have the potential to promote nutrient delivery via intestinal paracellular absorption.

The significance of plasma ascorbic acid (AA) is underscored by its enzymatic and antioxidant properties as well as involvement in many aspects of health including the synthesis of biomolecules during acute illness, trauma and chronic health conditions. Dietary intake supports maintenance of optimal levels with supplementation at higher doses more likely pursued. Transient increased intestinal paracellular permeability following high dose AA may be utilised to enhance delivery of other micronutrients across the intestinal lumen. The potential mechanism following dietary intake however needs further study but may provide an avenue to increase small intestinal nutrient co transport and absorption, including in acute and chronic illness.

Visceral Adiposity and Glucoregulatory Peptides are Associated with Susceptibility to Type 2 Diabetes: The TOFI_Asia Study.

OBJECTIVE: Ethnic differences in fat deposition contribute to type 2 diabetes (T2D). Identification of biomarkers that underpin dysglycemia are needed for better-targeted prevention and treatment. METHODS: The cross-sectional thin-on-the-outside-fat-on-the-inside (TOFI)_Asia study investigated adipose depots and clinical biomarkers as predictors of fasting plasma glucose (FPG) and insulin resistance (IR; assessed using the updated homeostatic model assessment of IR) in lean and overweight normo- and dysglycemic Chinese (n = 199) and Caucasian (n = 158) individuals. Multivariate least-angle regression models were used to identify predictors of FPG and IR. RESULTS: At similar age and BMI, Chinese individuals had lower body weight but had a greater percentage of total abdominal adipose tissue and a greater percentage of total visceral adipose tissue (VAT) (all P < 0.005). In Chinese individuals, FPG, hemoglobin A1c , fasting insulin, and triglycerides were higher, whereas HDL cholesterol and total and high-molecular-weight adiponectin levels were lower (all P < 0.0001). Raised liver enzyme and peptide concentrations (P < 0.02) were consistent with increased T2D risk. Lean Chinese women (<25 kg/m2 ) had greater total abdominal adipose tissue (kilograms) and VAT (kilograms) than Caucasian women, exhibiting the TOFI profile, with raised FPG (P < 0.001) and IR (P = 0.01). Risk factors for elevated FPG specific to Chinese individuals included male gender, VAT, and triglycerides (R2 = 0.33), and risk factors for IR specific to Chinese individuals included amylin, C-peptide, and glucagon (R2 = 0.49). VAT, amylin, and C-peptide were predictors in Caucasian individuals. CONCLUSIONS: VAT contributed to dysglycemia in both ethnicities, particularly in Chinese individuals characterized by the TOFI phenotype, as did the glucoregulatory peptides amylin and C-peptide, providing targets for T2D prevention.