SLC2A4 and type 2 diabetes mellitus: Studies observing beneficial effects of n-3 PUFA on type 2 diabetes and its parameters also used combined interventions such as n-3 PUFA with plant sterol or vitamin D. Both plant sterol and vitamin D are known to prevent impaired glucose regulation (IGR) progression to type 2 diabetes and enhance the insulin-regulated glucose transporter type-4 (GLUT-4), respectively, while improving blood glucose levels and insulin resistance [61,62].