The last fat-soluble vitamin we need to mention is Vitamin-K. We get plenty from the food we eat, and what we make in our bowels. All though Vitamin-K is fat soluble, we accumulate very little. We have at most 7 days of storage.
Sources for Vitamin K: leafy vegetables, vegetable oils, liver, & synthesis by what we make in our intestines. Phylloquinone (Vitamin K-1) is present primarily in green leafy vegetables and is the main dietary form of vitamin K. Menaquinones (Vitamin K-2), especially long-chain menaquinones, are produced by bacteria in the human gut.
Vitamin-K is necessary for activation of clotting factors.
Deficiency States: Can be due to:
• Excessive antibiotic use. Newborns & preemies are at increased risk.
• Cystic fibrosis patients because of fat malabsorption and broad-spectrum antibiotic use (that kills off bacteria that produces Vitamin-K) should be supplemented with Vitamin-K
• Vitamin-K stores are small- deficiency may develop in a week.
Interactions: warfarin, a 60-year-old drug for thinning the blood opposes Vitamin K in the clotting cascade. Warfarin patients need to be aware of food interactions with this drug.
Counseling points:
Lots of the foods we are told to eat to maintain a healthy and balanced diet are loaded with Vitamin-K. It is best we don’t discourage our patients from eating healthy. Here are some rough guidelines for Vitamin-K consumption if our patients are being managed on warfarin (Coumadin®).
· High in vitamin K foods: limit to (1) serving per day
o (kale, spinach, collard greens, Swiss chard, parsley)
· Moderately high: limit (3) servings per day
o (broccoli, Brussels sprouts, endive, green lettuce)
Best advice: eat a consistent diet!