@article{MorrisSaltRailaetal.2012, author = {Morris, Penelope J. and Salt, Carina and Raila, Jens and Brenten, Thomas and Kohn, Barbara and Schweigert, Florian J. and Zentek, Juergen}, title = {Safety evaluation of vitamin A in growing dogs}, series = {BRITISH JOURNAL OF NUTRITION}, volume = {108}, journal = {BRITISH JOURNAL OF NUTRITION}, number = {10}, publisher = {CAMBRIDGE UNIV PRESS}, address = {CAMBRIDGE}, issn = {0007-1145}, doi = {10.1017/S0007114512000128}, pages = {1800 -- 1809}, year = {2012}, abstract = {The safe upper limit for inclusion of vitamin A in complete diets for growing dogs is uncertain, with the result that current recommendations range from 5.24 to 104.80 mu mol retinol (5000 to 100 000 IU vitamin A)/4184 kJ (1000 kcal) metabolisable energy (ME). The aim of the present study was to determine the effect of feeding four concentrations of vitamin A to puppies from weaning until 1 year of age. A total of forty-nine puppies, of two breeds, Labrador Retriever and Miniature Schnauzer, were randomly assigned to one of four treatment groups. Following weaning at 8 weeks of age, puppies were fed a complete food supplemented with retinyl acetate diluted in vegetable oil and fed at 1ml oil/100 g diet to achieve an intake of 5.24, 13.10, 78.60 and 104.80 mu mol retinol (5000, 12 500, 75 000 and 100 000 IU vitamin A)/4184 kJ (1000 kcal) ME. Fasted blood and urine samples were collected at 8, 10, 12, 14, 16, 20, 26, 36 and 52 weeks of age and analysed for markers of vitamin A metabolism and markers of safety including haematological and biochemical variables, bone-specific alkaline phosphatase, cross-linked carboxyterminal telopeptides of type I collagen and dual-energy X-ray absorptiometry. Clinical examinations were conducted every 4 weeks. Data were analysed by means of a mixed model analysis with Bonferroni corrections for multiple endpoints. There was no effect of vitamin A concentration on any of the parameters, with the exception of total serum retinyl esters, and no effect of dose on the number, type and duration of adverse events. We therefore propose that 104.80 mu mol retinol (100 000 IU vitamin A)/4184 kJ (1000 kcal) is a suitable safe upper limit for use in the formulation of diets designed for puppy growth.}, language = {en} } @article{RailaRohnSchweigertetal.2011, author = {Raila, Jens and Rohn, Sascha and Schweigert, Florian J. and Abraham, Getu}, title = {Increased antioxidant capacity in the plasma of dogs after a single oral dosage of tocotrienols}, series = {The British journal of nutrition : an international journal devoted to the science of human and animal nutrition}, volume = {106}, journal = {The British journal of nutrition : an international journal devoted to the science of human and animal nutrition}, number = {7}, publisher = {Cambridge Univ. Press}, address = {Cambridge}, issn = {0007-1145}, doi = {10.1017/S0007114511000511}, pages = {S116 -- S119}, year = {2011}, abstract = {The intestinal absorption of tocotrienols (TCT) in dogs is, to our knowledge, so far unknown. Adult Beagle dogs (n 8) were administered a single oral dosage of a TCT-rich fraction (TRF; 40 mg/kg body weight) containing 32\% alpha-TCT, 2\% beta-TCT, 27\% gamma-TCT, 14\% delta-TCT and 25\% alpha-tocopherol (alpha-TCP). Blood was sampled at baseline (fasted), 1, 2, 3, 4, 5, 6, 8 and 12 h after supplementation. Plasma and chylomicron concentrations of TCT and alpha-TCP were measured at each time point. Plasma TAG were measured enzymatically, and plasma antioxidant capacity was assessed by the Trolox equivalent antioxidant capacity assay. In fasted dogs, levels of TCT were 0.07 (SD 0.03) mu mol/l. Following the administration of the TRF, total plasma TCT peaked at 2 h (7.16 (SD 3.88) mu mol/l; P<0.01) and remained above baseline levels (0.67 (SD 0.44) mu mol/l; P, 0.01) at 12 h. The TCT response in chylomicrons paralleled the increase in TCT in plasma with a maximum peak (3.49 (SD 2.06) mu mol/l; P, 0.01) at 2 h post-dosage. alpha-TCP was the major vitamin E detected in plasma and unaffected by TRF supplementation. The Trolox equivalent values increased from 2 h (776 (SD 51.2) mu mol/l) to a maximum at 12 h (1130 (SD 7.72) mmol/l; P<0.01). The results show that TCT are detected in postprandial plasma of dogs. The increase in antioxidant capacity suggests a potential beneficial role of TCT supplementation in the prevention or treatment of several diseases in dogs.}, language = {en} }