Vitamin K

Unknown Author

Very little vitamin K is stored in the body and absorbtion can be decreased by a diet with too much sugar and calcium

The RDA ranges from 5 micrograms for infants to 80 micrograms for adult men.

Little is stored in the body.

Too much sugar, over-use of antibiotics, excess vitamin E and too much calcium can all cause decreased absorption of vitamin K.

Where do you get vitamin K?

Vitamin K is found in green vegetables, cereals, cheese and liver, and in eggs and beef.

Bacteria in your gut are also an important source.


You need vitamin K for blood to clot properly, and for teeth and bones to form correctly.

Too much vitamin K

Toxicity is rare, but can happen if large amounts of synthetic vitamin K are taken. Symptoms include flushing, sweating and anaemia.

Too little vitamin K

Deficiency is rare in adults unless they suffer from conditions that disrupt absorption such as Crohn’s disease, cystic fibrosis and ulcerative colitis.

Vitamin K supplements

Multivitamin preparations usually contain small amounts of vitamin K; the rest should come from the diet and intestinal bacteria.

The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.