Cystic fibrosis affects 30,000 children and adults in the U.S., according to the Cystic Fibrosis Foundation. People with cystic fibrosis have a life span of about 30 to 40 years. Data show vitamin K deficiency is common in this group. Dietary management to improve or prevent the deficiency can decrease premature bone loss and decrease the elevated risk of internal bleeding associated with vitamin K deficiency.
Etiology of Vitamin K Malabsorption
People with cystic fibrosis produce excessive and abnormally thick mucus secretions from the epithelial layer of organs, which is a layer of cells that covers the internal and external surfaces of the body. The liver, gastrointestinal tract, sweat glands and respiratory track are commonly affected. Excess mucus in the gastrointestinal tract causes malabsorption of fat and of fat-soluble vitamins like vitamin K.
Biological Role in Cystic Fibrosis
Vitamin K is absorbed along with fat in the gastrointestinal tract. Vitamin K deficiency is a contributing factor in the development of increased fractures and osteoporosis, which are also common in cystic fibrosis patients. Vitamin K plays an important role in bone formation and blood clotting. People with cystic fibrosis have problems obtaining enough vitamin K from dietary sources; rich dietary sources include green, leafy vegetables and soybeans.
Vitamin K Supplementation
People with cystic fibrosis may benefit from vitamin K supplements in doses twice the recommended daily allowance, according to a study in the June 2001 issue of the "Journal of Pediatrics." The upper ranges of the U.S. Department of Agriculture RDA in healthy children, adolescents and adults are 10 mcg, 30 mcg and 80 mcg, respectively. Vitamin K supplements with 180 mcg improved vitamin K status in cystic fibrosis patients ranging in age from 6 months to 46 years.
Managing Vitamin K Deficiency and Risks
Deficiency in vitamin K may present as easy bruising, excessive bleeding, black stools, or blood in the feces or urine. Infants with cystic fibrosis who are vitamin K deficient are at risk for fatal bleeding in the skull. People with cystic fibrosis need a doctor and registered dietitian to monitor vitamin K levels for the prevention of disease-related bone loss. Talk with your doctor about starting any new supplements if you have cystic fibrosis.
References
- "American Journal of Epidemiology"; Epidemiology and Survival Analysis of Cystic Fibrosis in an Area of Intense Neonatal Screening Over 30 Years; Baroukh M. Assael, et al.; 2002
- UpToDate; Overview of Vitamin K; Sassan Pazirandeh, M.D., et al.
- "Cochraine Database of Systemic Reviews"; Vitamin K Supplementation for Cystic Fibrosis; V.A. Jagannath, et al.; January 2011
- "Thorax"; Osteoporosis and Osteopenia in Adults and Adolescents With Cystic Fibrosis: Prevalence and Associated Factors; S.P. Conway, et al.; 2000
- "Journal of Pediatrics"; Treatment of Vitamin K Deficiency in Cystic Fibrosis: Effectiveness of a Daily Fat-soluble Vitamin Combination; D.C. Wilson, et al.; June 2001
- Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc; National Academy of Sciences Institute of Medicine Food and Nutrition Board; 2001
