The available evidence on vitamin K status in cystic fibrosis (CF) is scarce, lacking data on vitamin K2 (menaquinones-MK). Therefore, we assessed vitamin K1, MK-4 and MK-7 concentrations (LC-MS/MS) in 63 pancreatic insufficient and modulator naïve CF patients, and compared to 61 healthy subjects (HS). Vitamin K1 levels did not differ between studied groups. MK-4 concentrations were higher (median <1st-3rd quartile>: 0.778 <0.589-1.086> vs. 0.349 <0.256-0.469>, p < 0.0001) and MK-7 levels lower (0.150 <0.094-0.259> vs. 0.231 <0.191-0.315>, p = 0.0007) in CF patients than in HS. MK-7 concentrations were higher in CF patients receiving K1 and MK-7 supplementation than in those receiving vitamin K1 alone or no supplementation. Moreover, vitamin K1 concentrations depended on the supplementation regime. Based on multivariate logistic regression analysis, we have found that MK-7 supplementation dose has been the only predictive factor for MK-7 levels. In conclusion, vitamin K1 levels in CF are low if not currently supplemented. MK-4 concentrations in CF patients supplemented with large doses of vitamin K1 are higher than in HS. MK-7 levels in CF subjects not receiving MK-7 supplementation, with no regard to vitamin K1 supplementation, are low. There do not seem to be any good clinical predictive factors for vitamin K status.

• Keywords
• cystic fibrosis, gastroenterology, liquid chromatography, pancreatic insufficiency, vitamin K1, vitamin K2,
• MeSH
• Cystic Fibrosis * blood   MeSH
• Adult MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Vitamin K Deficiency blood   MeSH
• Nutritional Status MeSH
• Dietary Supplements MeSH
• Prothrombin * analysis   MeSH
• Cross-Sectional Studies MeSH
• Vitamin K 1 * administration & dosage   blood   MeSH
• Vitamin K 2 * blood   analogs & derivatives   MeSH
• Vitamin K blood   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Adolescent MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• menaquinone 7 MeSH Browser
• menatetrenone MeSH Browser
• Prothrombin * MeSH
• Vitamin K 1 * MeSH
• Vitamin K 2 * MeSH
• Vitamin K MeSH

Vitamin K is traditionally connected with blood coagulation, since it is needed for the posttranslational modification of 7 proteins involved in this cascade. However, it is also involved in the maturation of another 11 or 12 proteins that play different roles, encompassing in particular the modulation of the calcification of connective tissues. Since this process is physiologically needed in bones, but is pathological in arteries, a great deal of research has been devoted to finding a possible link between vitamin K and the prevention of osteoporosis and cardiovascular diseases. Unfortunately, the current knowledge does not allow us to make a decisive conclusion about such a link. One possible explanation for this is the diversity of the biological activity of vitamin K, which is not a single compound but a general term covering natural plant and animal forms of vitamin K (K1 and K2) as well as their synthetic congeners (K3 and K4). Vitamin K1 (phylloquinone) is found in several vegetables. Menaquinones (MK4-MK13, a series of compounds known as vitamin K2) are mostly of a bacterial origin and are introduced into the human diet mainly through fermented cheeses. Current knowledge about the kinetics of different forms of vitamin K, their detection, and their toxicity are discussed in this review.

• Keywords
• bioanalysis, coagulation, diet, menaquinone, phylloquinone,
• MeSH
• Kinetics MeSH
• Humans MeSH
• Osteoporosis * MeSH
• Vitamin K 1 MeSH
• Vitamin K 2 MeSH
• Vitamin K * MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• Vitamin K 1 MeSH
• Vitamin K 2 MeSH
• Vitamin K * MeSH