Some health problems can make it hard for a person's body to absorb these vitamins. If you have a chronic health condition, ask your doctor about whether your vitamin absorption will be affected.
How Much Vitamin K Is Enough?
Women should consume 65 micrograms a day of vitamin K, and men should consume 80 micrograms a day of vitamin K.
Sources of Vitamin K
About half of the vitamin K necessary for good health is supplied by bacteria living in the intestine, but dietary consumption of vitamin K is also important. Good sources of vitamin K include:
- Dark, leafy green vegetables such as spinach or kale
- Beef liver
- Green tea
Can You Have Too Much or Too Little?
Newborns are especially prone to vitamin K deficiency, so the American Academy of Pediatrics recommends vitamin K supplementation. Vitamin K deficiency in adults is rare but it may occur in people with conditions such as cystic fibrosis and celiac disease whose bodies cannot absorb vitamins from foods properly. When it occurs, vitamin K deficiency may cause bleeding gums and skin that is easily bruised.
Vitamin K toxicity is also rare, but you should not take doses of more than 500 micrograms without talking to your doctor. Vitamin K may interfere with the effectiveness of medications such as anticoagulants (also known as blood thinners), so talk to your doctor before using a supplement that contains vitamin K.
If you want to get the most vitamins possible from your food, refrigerate fresh produce and keep milk and grains away from strong light. Vitamins are easily destroyed and washed out during food preparation and storage. If you take vitamin supplements, store them at room temperature in a dry place that's free of moisture.