August 2016

Vitamin D Supplementation Reduces Insulin Resistance

A recent clinical trial shows that taking vitamin D3 420 IU daily for one year significantly reduces insulin resistance, as measured by the homeostasis model, from 1.17 to 0.84 in healthy adults. Fasting glucose levels also significantly decreased from 88.3 to 85.3 mg/dL. These results were independent of physical activity levels and weight gain in the abdominal area. No significant changes were seen in the placebo group.

For more information about vitamin D, please review our complete scientific monograph.


  1. Sun X, Cao Z-B, Tanisawa K, et al. Vitamin D supplementation reduces insulin resistance in Japanese adults: a secondary analysis of a double-blind, randomized, placebo-controlled trial. Nutrition Research. 2016. DOI:

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