Sharon Evans1, Anne Daly1, John K MacDonald1, Mary Anne Preece1, Saikat Santra1, Suresh Vijay1, Anupam Chakrapani1, Anita MacDonald1
1Birmingham Children’s Hospital, Birmingham, UK
Tóm tắt
<b><i>Background:</i></b> In phenylketonuria (PKU), phenylalanine-free <smlcap>L</smlcap>-amino acid supplements are the major source of dietary micronutrients. <b><i>Methods:</i></b> Four hundred fifty-two retrospective annual/bi-annual non-fasting blood samples for nutritional markers (plasma zinc, selenium, and serum folate) from 78 subjects aged 1-16 years (median number of blood samples: 6, range 1-14) were analysed over 12 years. Longitudinal blood result data were available for 51 subjects (65%). The dietary intake from supplements was calculated. <b><i>Results:</i></b> The median intakes of all of the micronutrients studied were >200% of the reference nutrient intakes (RNI). There was no statistical correlation between dietary intake and nutritional markers outside of the normal reference range (RR) except for selenium, but there was a correlation between a lower plasma zinc, plasma selenium and haemoglobin status and better blood phenylalanine control in 1- to 4-year-old children. On at least one occasion, the individual plasma concentrations of zinc (71%, n = 54/76) and selenium (21%, n = 16/75) were below the RR; however, the concentrations of selenium (41%, n = 31/75) and serum folate (83%, n = 34/41) were also above the RR. Dietary intakes exceeded the upper tolerable intakes for zinc and copper (32%, n = 25) and folate (65%, n = 51). Individual longitudinal data demonstrated little change in micronutrient status over time. <b><i>Conclusions:</i></b> In PKU, biochemical micronutrient deficiencies are common despite micronutrient intakes above the RNI. Further study of the nutritional profiling of <smlcap>L</smlcap>-amino acid supplements in PKU is needed.
