Vitamin E intake, α-tocopherol levels and pulmonary function in children and adolescents with cystic fibrosis

Pancreatic insufficiency cystic fibrosis (CF) patients receive vitamin E supplementation according to CF-specific recommendations in order to prevent deficiencies. It has been suggested that higher serum alpha-tocopherol levels could have protective effects on pulmonary function (PF) in patients with CF. Whether current recommendations are indeed optimal for preventing deficiency and whether vitamin E has therapeutic benefits are subjects of debate. Therefore, we studied vitamin E intake as well as the long-term effects of vitamin E intake, the coefficient of fat absorption (CFA) and IgG on alpha-tocopherol levels. We also examined the long-term effects of serum alpha-tocopherol and serum IgG on forced expiratory volume in 1 s expressed as percentage of predicted (FEV1% pred.) in paediatric CF patients during a 7-year follow-up period. We found that CF patients failed to meet the CF-specific vitamin E recommendations, but serum alpha-tocopherol below the 2.5th percentile was found in only twenty-three of the 1022 measurements (2 %). Furthermore, no clear effect of vitamin E intake or the CFA on serum a-tocopherol was found (both P >= 0.103). FEV1% pred. was longitudinally inversely associated with age (P<0.001) and serum IgG (P=0.003), but was not related to serum alpha-tocopherol levels. We concluded that in the present large sample of children and adolescents with CF, vitamin E intake was lower than recommended, but serum alpha-tocopherol deficiency was rare. We found no evidence that higher serum alpha-tocopherol levels had protective effects on PF. Adjustment of the recommendations to the real-life intake of these patients may be considered.