Science Update

Recent Study Indicates Supplementation of Tocotrienol-Rich Vitamin E Supports Kidney Function

The physiological benefits of vitamin E tocotrienols are well-known, as evidenced by the scientific literature. Vitamin E tocotrienols contain properties that vitamin E tocopherols lack, such as the commonly used alpha-tocopherols. Research has shown that vitamin E tocotrienols (particularly the delta- and gamma-isomers) possess cytotoxic effects associated with the induction of apoptosis in various cancers, including ovarian cancer. Vitamin E tocotrienols may also be beneficial as an adjunct in the treatment of metabolic syndrome, type 2 diabetes, nonalcoholic fatty liver disease, and age-related eye disorders.

A recent human, clinical trial published in Nutrients investigated the effects of supplementation with tocotrienol-rich vitamin E on diabetic kidney disease (DKD). In this randomized, double-blind, placebo-controlled trial, researchers evaluated DKD patients for the effects of tocotrienol-rich vitamin E supplementation with 200 mg twice per day for 12 months from among a study of 59 DKD patients with 31 patients who were placed in the intervention group and 28 in the placebo group. Renal parameters, anti-fibrotic biomarkers, and hemoglobin A1c (HbA1c) were collected from all patients every 2 months to monitor adverse events and compliance.

DKD “is a debilitating microvascular complication of diabetes progressing to end-stage renal failure (ESRF)” whose pathophysiology is multifaceted and not fully understood. However, the overproduction of advanced glycation end products and byproducts from major metabolic pathways (including the protein kinase C, polyol, and hexosamine pathways) caused by chronic hyperglycemia often results in microvascular and macrovascular complications of diabetes, specifically upregulating endothelial activity in the renal glomeruli.

After 8 months, tocotrienol-rich vitamin E supplementation demonstrated improved kidney function parameters by significantly reduced serum creatinine levels and significantly increased estimated glomerular filtration rate (eGFR) compared to a placebo. No changes were found in renal parameters at 12 months, which suggested that the renoprotective effects of tocotrienols may only be sustained until 8 months post-supplementation. No significant changes were observed in urea, uric acid, anti-fibrotic parameters, or HbA1c.

Adopting a low-glycemic diet, abundant in potassium-rich vegetables and fruits, and increasing physical activity may be the first line of defense for supporting kidney health and managing blood glucose and insulin metabolism in DKD. In addition, resveratrol supplementation in vitro and in human clinicals has shown positive effects in diabetic nephropathy and kidney disease due to its powerful antioxidant and anti-inflammatory properties. Vitamin E tocotrienols have antioxidant properties that may be an additional clinically relevant tool for supporting kidney function and potentially reducing the progression of diabetic kidney disease, along with a potential reduction in the risk of developing ESRF. More long-term, human trials are needed to confirm the beneficial effects of vitamin E tocotrienols on kidney health in diabetic patients.

By Caitlin Higgins, MS, CNS, LDN