Efficacy of high dose phylloquinone in correcting vitamin K deficiency in cystic fibrosis

Abstract Background Subclinical deficiencies of vitamin K are universally present in unsupplemented cystic fibrosis (CF) patients. The dose required to prevent deficiencies cannot be estimated from the existing literature. The aim of this study is determine if a supplemental dose of 1 mg/day or 5 mg/day vitamin K 1 per day would normalize vitamin K status in a population of children with cystic fibrosis. Methods Fourteen pancreatic insufficient CF children, between the ages of 8 to 18 years old, were randomized to receive either 1 mg/day or 5 mg/day vitamin K 1 per day, for one month. Fasting blood tests were done at baseline and after one month of the intervention. The degree of undercarboxylation of osteocalcin (%Glu-OC), and serum vitamin K 1 , were evaluated by descriptive statistics and nonparametric Wilcoxon matched-pair test and Mann–Whitney U test. Results Of the 50% of subjects who were below the optimal serum vitamin K 1 at baseline, all rose into the normal range with supplementation. Supplementation also significantly reduced the overall %Glu-OC from a median of 46.8 to 29.1% ( p Conclusion Our results suggest that both 1 mg and 5 mg of vitamin K 1 , given over a one-month period in pancreatic insufficient pediatric cystic fibrosis patients improve vitamin K status.