Suboptimal vitamin K status despite supplementation in children and young adults with cystic fibrosis

Am J Clin Nutr. 2010 Sep;92(3):660-7. doi: 10.3945/ajcn.2010.29350. Epub 2010 Jun 16.


Background: For children and adolescents with cystic fibrosis (CF) and pancreatic insufficiency, the efficacy of routine vitamin K supplementation to normalize vitamin K status remains unclear.

Objective: This study examined and determined predictors of vitamin K status in subjects aged 8-25 y with CF and pancreatic insufficiency taking various vitamin K supplements.

Design: In 97 subjects, serum 25-hydroxyvitamin D [25(OH)D], dietary intake, vitamin K supplement intake, and vitamin K statusmdashdetermined on the basis of the percentage of serum undercarboxylated osteocalcin (%ucOC; sufficient: lt 20%) and plasma proteins induced by vitamin K absence-factor II (PIVKA-II; n = 60; sufficient: le 2 microg/L)mdashwere assessed. The vitamin K supplementation groups were as follows: lt 150 microg/d (low; multivitamins or no supplement), 150-999 microg/d (middle; CF-specific vitamins), and ge 1000 microg/d (high; mephyton). %ucOC values were compared with 140 healthy subjects aged 6-21 y.

Results: In subjects with CF, the median (range) %ucOC was 35% (3%, 76%) and the median (range) for PIVKA-II was 2 (0, 42) micro g/L. Subjects with CF had a higher %ucOC with low [45% (10%, 76%)] and medium [41% (3%, 66%)] supplement intakes but not with a high supplement intake [16% (4%, 72%)] compared with healthy subjects [23% (0%, 43%); both P lt 0.05]. Supplementation group for males and females and 25(OH)D and age for males were significant predictors of vitamin K status.

Conclusions: Vitamin K status was often suboptimal despite routine supplementation. Only subjects taking high-dose vitamin K achieved a status similar to healthy subjects, and only the vitamin K supplementation dose predicted vitamin K status for males and females. These data suggest that higher doses of vitamin K are required.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Case-Control Studies
  • Child
  • Cystic Fibrosis / blood
  • Cystic Fibrosis / complications
  • Cystic Fibrosis / drug therapy*
  • Dietary Supplements
  • Female
  • Humans
  • Male
  • Nutritional Status*
  • Osteocalcin / blood
  • Pancreatic Diseases / complications
  • Pancreatic Diseases / drug therapy*
  • Prothrombin / metabolism
  • Sex Factors
  • Vitamin D / analogs & derivatives
  • Vitamin D / blood
  • Vitamin K / administration & dosage
  • Vitamin K / blood
  • Vitamin K / therapeutic use*
  • Vitamin K Deficiency / drug therapy*
  • Vitamin K Deficiency / etiology
  • Vitamins / administration & dosage
  • Vitamins / blood
  • Vitamins / therapeutic use*
  • Young Adult


  • Vitamins
  • Osteocalcin
  • Vitamin K
  • Vitamin D
  • Prothrombin
  • 25-hydroxyvitamin D