Vitamin K & The Minimum Daily Dose

Vitamin K belongs to a group of vitamins called fat-soluble vitamins. Fat-soluble vitamins require the presence of dietary fat to be properly absorbed by the body. In addition, the body has the ability to store fat-soluble vitamins for later use. To keep your stores of vitamin K within normal ranges, it is important to consume an adequate amount of vitamin K through your diet every day.

Functions

One of the most well-known functions of vitamin K is its role in blood clotting. For blood to clot properly, several proteins called coagulation factors must be available in the blood. Vitamin K allows the synthesis of four of these vital coagulation factors. If you do not consume enough vitamin K on a regular basis, bleeding would be uncontrollable.

Vitamin K also acts as a coenzyme, substances that ensure that chemical reactions are able to take place. Vitamin K makes it possible for the bone protein, osteocalcin, to combine with calcium, which can help make your bones strong.

Types of Vitamin K

Vitamin K exists in two forms: menaquinone and phylloquinone. The bacteria that normally live in your intestine synthesize the menaquinone form of vitamin K. Vitamin K is one of the few vitamins that can be produced in your body. Dietary vitamin K exists in the form of phylloquinone.

Daily Recommendations

It is unclear exactly how much vitamin K the bacteria in your intestinal tract contribute, so this type of vitamin K is not considered in calculating your daily needs. The Food and Nutrition Board, which is a subgroup of the Institutes of Medicine, recommends that adult women consume at least 90 micrograms of vitamin K daily, whereas adult men should consume 120 micrograms daily.

Food Sources

Green plants are the richest sources of dietary vitamin K. Excellent sources of vitamin K include asparagus, spinach, broccoli, Brussels sprouts, cabbage and salad greens. Other good sources of vitamin K include margarine and vegetable oils.

Considerations

Vitamin K has not been shown to be toxic in large amounts, so the Food and Nutrition Board has not set an upper tolerable intake level, or UL. Although deficiency is possible, it is rare in healthy individuals and usually only occur in those with illnesses that affect the proper absorption of fat in the intestinal tract, according to "Nutrition and You" by Joan Salge Blake.