Whole Egg Consumption Completely Prevents Vitamin D Deficiency in Type 2 Diabetic Rats

Abstract

Previous research has shown that type 2 diabetes (T2D) is characterized by vitamin D deficiency and nephropathy. Whole eggs are a rich source of vitamin D in the diet, particularly 25-OH-vitamin D (25D), the precursor form of active vitamin D in the circulation that reflects vitamin D status. Thus, the goal of this study was to determine if whole egg consumption could maintain vitamin D balance in T2D rats. Zucker diabetic fatty (ZDF) rats (n= 10) and their lean controls (n=10) were each randomly assigned to 2 diet groups: a control AIN93 casein-based diet or the same diet containing whole egg in place of casein, both provided at 20% (w/w). Corn oil was added to the casein-based diet to achieve the same total lipid content as the whole egg-based diet. Prior to sacrifice, animals were fasted for 12 h. Urinary creatinine, blood glucose and serum 25D were analyzed. Whole egg consumption attenuated hyperglycemia by 48% and reduced total weight gain by 40% in ZDF rats compared to the ZDF rats fed the casein-based diet. As expected, circulating 25D decreased 53% in the casein-fed ZDF rat compared to the casein-fed lean control group. However, ZDF rats fed whole egg exhibited circulating 25D levels that were the same as casein-fed lean control rats. Whole egg also resulted in a 2-fold increase in circulating 25D in the lean control group, but did not impact diminished creatinine excretion in ZDF rats. These data strongly suggest that dietary consumption of whole egg can attenuate hyperglycemia, stabilize weight gain, and maintain normal circulating 25D concentrations in T2D rats. This finding may support new dietary intervention strategies or recommendations that target the prevention of vitamin D deficiency in T2D. Support: Egg Nutrition Center.