Effects of vitamin C and L-carnitine supplementation on metabolic parameters during fasting and re-feeding

Abstract

Background: Fasting as a means of protest or religious purposes have  increased in the last two decades, individuals involved take only water and supplements. This study investigated the roles of vitamin C and  L-carnitine on metabolic parameters during fasting and re-feeding.

Methods: Sixty male Sprague-Dawley rats (170-180 g) were divided into ten groups of control, fasting, fasting + vitamin C and fasting + L-carnitine. The test groups were further divided into recovery 1  (recovery 1= 24 hours of feeding following a 72 hours fast) and recovery 3 (recovery 3 = 72 hours of feeding following a 72 hours fast) groups. During fasting, rats were allowed water intake and fasting blood glucose was taken daily. The rats were sacrificed on day 3 of the fast and serum obtained for insulin and leptin assays.

Results: Fasted rats lost 25% of body weight and recovered only about 11% of the body weight in three days following the fast. Neither vitamin C nor L-carnitine supplementation improved the weights of the animals during recovery. FBG and liver glycogen stores were significantly  decreased in 72 hours alongside with insulin levels and leptin in the fasted rats. Neither vitamin C nor L-carnitine provided beneficial effects but L-carnitine was found to increase leptin levels during the fast.

Conclusion: The study showed that neither vitamin C nor L-carnitine supplementations improved the catabolic effects of fasting in rats though a long term recovery period might portray a better result.

Key words: Vitamin C, L-carnitine, Fasting, Re-feeding, leptin, insulin