Unrestricted fruits and vegetables in the PKU diet: a 1-year follow-up.

Phenylketonuria (PKU) therapy demands phenylalanine (Phe) calculation. In most countries, almost all food is taken into account, even fruits and vegetables. We investigated whether unrestricted consumption of fruits and vegetables negatively influences metabolic control. Nineteen PKU children (2-10 years) started with 2 weeks of free or restricted fruit and vegetable intake. After 2 weeks, the regime changed from free to restricted or restricted to free (cross-over design). Over the first 4 weeks, dried blood Phe concentration was measured, fruit and vegetable consumption recorded and nutrient intake calculated from diet records. Thereafter the diet was changed to free use of fruits and vegetables for all patients. Six and 12 months later, diet and Phe concentrations were monitored. Median Phe intake increased significantly by 65 mg/day (week 4, P<0.001), 68 mg/day (month 6, P<0.001) and 70 mg/day (month 12, P<0.001). Dried blood Phe concentrations remained stable (P=0.894), as did the frequency of Phe concentrations above the recommended range (P=0.592). In conclusion, PKU diet liberalization for fruits and vegetables seems unproblematic.

Investigation into selenium requirement of growing turkeys offered a diet supplemented with two levels of vitamin E.

To evaluate dietary selenium (Se) requirement in turkeys offered a diet supplemented with two levels of vitamin E (VE), 96 newly hatched male BIG 6 chicks (58.4 +/- 4.12 g) were divided into eight groups of 12 animals each and fed maize soya diets containing 0.05, 0.10, 0.20 and 0.30 mg Se/kg from sodium selenate in combination either with the natural VE content (approximately 10 IU/kg) or with a VE addition of 50 IU/kg. Animals from all the groups were highly performant and their final body weights (1746 +/- 190 g) after 35 days on experiment were not significantly different. According to its dietary supply, Se concentration in the liver and plasma increased dose dependently. Independent of dietary VE, the activities of GPx3 in plasma and of GPx1 in liver and breast muscle increased to a larger extent in turkeys supplemented with 0.10 and 0.20 mg Se/kg in relation to animals with low marginal Se supply (0.05 mg/kg). Supplementation of 0.30 mg Se/kg only slightly increased further selenoprotein activities. 2-Thiobarbituric acid reactive substances in the liver were strongly reduced by dietary VE, but not by Se. Plasma aspartate aminotransferase (AST) and creatine kinase (CK) activities did not show muscular lesions in none of the groups. Although there were no signs of muscular lesions even in turkeys with marginal Se and moderate VE supply, the activity of selenoproteins in various organs increased up to 0.30 mg Se/kg diet, independent of VE supply. It was concluded that for growing turkeys the Se supply should meet at least a level of 0.20 mg/kg diet as currently recommended by the National Research Council and Gesellschaft für Ernährungsphysiologie. Vitamin E addition confirmed the particular function of the vitamin as a lipid antioxidant and should be taken into consideration when diets with high PUFA concentrations are fed.