Phylloquinone - Vitamin K1

Phylloquinone and phytonadione are two forms of vitamin K1. Both may be derived from menaquinone - vitamin K2. Vitamin K1 is found naturally in plants. Vitamin K2 is synthesized by bacteria in the intestinal tract. Vitamin K is a fat-soluble vitamin which is absorbed in the presence of bile and pancreatic juices, and is enhanced by dietary fat.

Vitamin K is moderately stable to heat, but unstable to light, acid, and alkali conditions. It is essential for the blood clotting mechanism and is needed for the synthesis of prothrombin, a protein which converts soluble fibrinogen circulating in the blood into very insoluble protein called fibrin, the major component of a blood clot.

Vitamin K plays an essential role in the production of carboxyglutamyl residues from the amino acid, glutamic acid. It is absorbed in the gut and transported by chylomicrons (microscopic lipid particles that transport fat-soluble components through the lymphatic system).

FOOD SOURCES

Cruciferous vegetables, green tea, beef liver, egg yolks, whole wheat, oats, soybeans, potatoes, butter, cheese, asparagus, tomatoes.

SUPPLEMENTATION

Menadione is a synthetic form of vitamin K3 which can be converted into vitamin K2 in the intestinal tract, but its use should be avoided as it has shown evidence of toxicity. The natural forms, K1 and K2 have no known toxicity. Pregnant or lactating women should consult their health care professional before taking Vitamin K supplements.

SIGNS OF DEFICIENCY

Vitamin K deficiencies are rare, except for newborns. Fatal intracranial haemorrhage is a risk to newborns that do not receive a vitamin K injection at birth. Synthetic versions should not be used for this purpose.

SIGNS OF TOXICITY

There are no known toxic effects for the natural forms, K1 and K2. Synthetic forms, K3, K4, K5 do exhibit toxic effects at elevated levels.

DAILY REQUIREMENT

Approx. 70mcg.