Impact of lipophilic antioxidants and level of antibodies against oxidized low-density lipoprotein in Polish children with phenylketonuria.

The treatment of phenylketonuria (PKU) patients constitutes a phenylalanine (Phe) intake restriction in their diet, which is achieved by adding a special Phe-free amino acid mixture to the diet. It has been reported that this diet could have some micronutrient deficiency. Several authors have also reported an increased oxidative stress or impaired antioxidant status in human and experimental PKU. Our project assessed the concentrations of retinol, alpha-tocopherol, coenzyme Q10, and anti-oxidized low-density lipoprotein (ox-LDL) antibodies in PKU children's plasma. It was found that retinol concentration in PKU children remains within the norm despite a low intake. The lower plasma alpha-tocopherol concentration in PKU children compared with normal children was associated with the lower level of antibodies against ox-LDL. This raises the question whether higher than observed circulatory alpha-tocopherol is indeed beneficial to lower plasma ox-LDL levels. Further studies are needed to explain the genetic factor in PKU patients (e.g., CD36/FAT polymorphism gene). The open clinical question is whether daily supplementation of alpha-tocopherol changes the PKU patients' level of antibodies against ox-LDL.

Vitamin D supplementation and status in infants: a prospective cohort observational study.

OBJECTIVE: Vitamin D status in infants depends on supplementation. We examined the vitamin D status in relation to supplementation dose and scheme in infants. PATIENTS AND METHODS: One hundred thirty-four infants age 6 months and 98 infants age 12 months (drop out 27%) were investigated. Vitamin D intake (diet, supplements), anthropometry, and 25-hydroxyvitamin D (25-OHD) serum concentration at the 6th and 12th months were assessed. RESULTS: Vitamin D intake of 1062 ± 694 IU at the 6th month was not different from that at the 12th month (937 ± 618 IU). Vitamin D intake expressed in international units per kilogram of body weight decreased from 141 ± 80 IU/kg at the 6th month to 93 ± 62 IU/kg at the 12th month (P < 0.0001), which was associated with a reduction in 25-OHD from 43 ± 20 ng/mL to 29 ± 12 ng/mL, respectively (P < 0.0001). In the subgroup of everyday supplemented infants (n = 43), vitamin D intake decreased from 143 ± 88 IU/kg at the 6th month to 118 ± 60 IU/kg at the 12th month (P < 0.05), which coincided with a reduction of 25-OHD from 40 ± 19 ng/mL to 32 ± 13 ng/mL (P < 0.01). In the subgroup with variable supplementation habits (n = 32), vitamin D intake decreased from 146 ± 79 IU/kg to 77 ± 56 IU/kg (P < 0.001), which was associated with a reduction of 25-OHD from 42 ± 21 ng/mL to 25 ± 8 ng/mL (P < 0.0001). 25-OHD concentration change between the 6th and the 12th months negatively correlated with the 25-OHD level assessed at the 6th month (r = -0.82; P < 0.0001). CONCLUSIONS: Vitamin D supplementation of infants should consider their rapid body weight increment. We postulate vitamin D daily dose close to 100 IU/kg body weight as favorable for infants up to age 12 months.