Vitamin K

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!