In T2DM male Sprague Dawley rats, 1.0% w/w VA supplementation in a diet containing butter oil as the dairy background improves fasting blood glucose and glucose-stimulated insulin secretion in vivo and from isolated islets [94], which is associated with increased β-cell area and up-regulation of the FA receptor GPR40 in islets [94]. The gene discussed is INS; the disease is type 2 diabetes mellitus.