[Tissue thiamine, riboflavin and vitamin B6 in the aged rat. II. Effects of vitamin supplementation in the diet on the excretion of vitamins and its tissue levels].

Nine and twenty-one months old rats fed a balanced diet were given for 5 weeks an extra supplementation in thiamine, riboflavin and vitamin B6. Control animals were given the same diet but without vitamin extra supplementation. Fecal and urinary vitamin excretions were determined during this 5 weeks period. They were shown to be less important in older rats than in younger ones. Influence of aging and vitamin supplementation on the vitamin contents of organs and tissues were studied on these animals: previous results were confirmed [see LECLERC, Ann. nutrit, Aliment., 1976, 30, 10--25]. From these results and others published elsewhere, it is conclused that in older animals there could be an increased intestinal destruction of the above mentionned vitamin although changes in vitamin metabolism can be involved too.