Prolonged starvation changes energy metabolism; therefore, the metabolic response to starvation is divided into three phases according to changes in glucose, lipid and protein utilisation. B-group vitamins are involved in energy metabolism via metabolism of carbohydrates, fatty acids and amino acids. To determine how changes in energy metabolism alter B-group vitamin concentrations during starvation, we measured the concentration of eight kinds of B-group vitamins daily in rat blood, urine and in nine tissues including cerebrum, heart, lung, stomach, kidney, liver, spleen, testis and skeletal muscle during 8 d of starvation. Vitamin B 1 , vitamin B 6 , pantothenic acid, folate and biotin concentrations in the blood reduced after 6 or 8 d of starvation, and other vitamins did not change. Urinary excretion was decreased during starvation for all B-group vitamins except pantothenic acid and biotin. Less variation in B-group vitamin concentrations was found in the cerebrum and spleen. Concentrations of vitamin B 1 , vitamin B 6 , nicotinamide and pantothenic acid increased in the liver. The skeletal muscle and stomach showed reduced concentrations of five vitamins including vitamin B 1 , vitamin B 2 , vitamin B 6 , pantothenic acid and folate. Concentrations of two or three vitamins decreased in the kidney, testis and heart, and these changes showed different patterns in each tissue and for each vitamin. The concentration of pantothenic acid rapidly decreased in the heart, stomach, kidney and testis, whereas concentrations of nicotinamide were stable in all tissues except the liver. Different variations in B-group vitamin concentrations in the tissues of starved rats were found. The present findings will lead to a suitable supplementation of vitamins for the prevention of the re-feeding syndrome.Key words: Starvation: Fasting: Energy metabolism Starvation produces a series of metabolic changes that lead to a reduction in body weight, alterations in body composition and metabolic gene expression (1,2) . In mammals and birds, three distinct levels of energy depletion have been established (3 -10) . The first phase (phase 1) is a rapid period of adaptation marked by an increase in mobilisation of fat stores and a lowering in protein utilisation. During the second phase (phase 2), which is a long period of thrift, most of the energy expenditure is derived from fats, and then fat stores are progressively exhausted, while body proteins are efficiently spared. The third phase (phase 3) is characterised by an increase in protein utilisation. In humans, the negative energy balance resulting from starvation can arise due to disease, eating or psychological disorders, or hunger strikes. Starvation and consequent re-feeding syndrome can lead to electrolyte disorders, especially hypophosphataemia, along with neurological, pulmonary, cardiac, neuromuscular and haematological complications (11) . To avoid the re-feeding syndrome, an additional load of vitamins has been suggested to correct the vitamin deficiencies (11) . ...

B-vitamins are important for producing energy from amino acids, fatty acids, and glucose. The aim of this study was to elucidate the effects of excess vitamin intake before starvation on body mass, organ mass, blood, and biological variables as well as on urinary excretion of riboflavin in rats. Adult rats were fed two types of diets, one with a low vitamin content (minimum vitamin diet for optimum growth) and one with a sufficient amount of vitamins (excess vitamin diet). Body mass, organ mass, and blood variables were not affected by excess vitamin intake before starvation. Interestingly, urinary riboflavin excretion showed a different pattern. Urine riboflavin in the excess vitamin intake group declined gradually during starvation, whereas it increased in the low vitamin intake group. Excess vitamin intake before starvation does not affect body mass, organ mass, or blood variables but does affect the urinary excretion of riboflavin in starving rats.

The present study aims to determine the most suitable dietary balance of energy-producing nutrients for recovery from starvation. Rats were fed their standard highcarbohydrate diet (HCD, carbohydrate energy : protein energy : fat energy571 : 18 : 11) for 7 d and then deprived of food for 3 d (short-term starvation) or 8 d (long-term starvation). The starved rats were then fed the HCD, a high-protein diet (HPD, 31 : 57 : 12), or a high-fat diet (HFD, 34 : 14 : 52) for 8 d. Rats had ad libitum access to drinking water throughout the experimental period, including the starvation period. The reference group was allowed free access to the HCD throughout the experimental period. Characteristically, increased drinking, increased urea nitrogen in the plasma and urine, and hypertrophy of the kidneys, were observed in the HPD group. Furthermore, the recovery of plasma glucose level was insufficient in this group. Therefore, administration of a HPD was contraindicated in recovery from starvation. The recovery of body weight after starvation was excellent in the HFD group. No effect on the metabolism of B-group vitamins involved in energy metabolism was found with the administration of any diet. The effects of HCD and HFD administration on recovery from starvation were investigated in further detail. No adverse effects were observed on the tissue to body weight mass ratios or biochemical parameters in blood in the HFD group. From the above findings, it is hypothesized that a HFD is most suitable for quickly reversing the influence of starvation.

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