Dark leafy greens are rich in vitamin K.
Vitamin K aids the body in cell growth, bone production and blood clotting. The recommended dietary allowance for vitamin K for adults is 90 to 120 mcg per day.
The body excretes vitamin K quickly. Therefore, people should attempt to eat foods rich in vitamin K every day. According to the USDA, Americans younger than 45 often get too little vitamin K in their diet.
Sources
A serving of chard provides the recommended dietary allowance of vitamin K.
Dark leafy greens are the best sources of vitamin K. The foods with the highest levels of vitamin K are kale, chard, turnip greens, spinach and collard greens. Other leafy greens, such as endive, beet greens, mustard greens, dandelion greens, watercress, green leaf lettuce and parsley, contain more than the RDA of the vitamin. Broccoli, Brussels sprouts, asparagus and green onions also have very high levels of vitamin K.
Foods with high amounts---60 to 90 mcg---of vitamin K per serving are okra, prunes, black-eyed peas and Chinese cabbage.
Foods with moderate amounts---30 to 60 mcg---of vitamin K per serving are cabbage, romaine lettuce, rhubarb, snap beans, peas, cucumber with the peel, celery, soybeans, tuna packed in oil, blueberries, pumpkin and kiwi.
Bone Health
Vitamin K may protect the body against osteoporosis.
Vitamin K is linked with reduced bone loss for older adults. Because of this, vitamin K may prevent osteoporosis, a disease that makes bones brittle.
The USDA states that people may need more than the RDA for optimal bone health. In a 2010 study, the USDA's Agricultural Research Service gave young men and women either four times the RDA of vitamin K or the RDA amount. Researchers found that the participants' bodies were able to produce more proteins involved in bone formation with the higher amount of vitamin K than with the RDA amount.
The current RDA reflects the amount of vitamin K needed for healthy blood clotting.
Preparation
Cooking foods with oil helps the body absorb vitamin K.
Cooking and freezing foods does not diminish vitamin K levels.
For the body to absorb vitamin K, meals must be eaten or prepared with fats. Preparing or serving foods with vitamin K in soybean oil, canola oil, olive oil or margarine will add extra vitamin K to meals since these oils also contain vitamin K.
Other sources
Older adults should take a daily multivitamin containing vitamin K.
Bacteria in the body's intestines produce a form of vitamin K, but researchers do not know how much vitamin K these bacteria produce. Researchers used to think intestinal bacteria produced 50 percent of a person's RDA, but now researchers believe this number is much less.
Many over-the-counter multivitamins contain vitamin K in amounts from 10 to 25 mcg, while bone health supplements contain 10 to 120 mcg. The Linus Pauling Institute at Oregon State University recommends adults, especially those older than 65, take a multivitamin and eat 1 cup of dark leafy greens daily.
Tags: leafy greens, absorb vitamin, allowance vitamin, amount vitamin, blood clotting, body absorb, body absorb vitamin