Vitamin K

The human body stores Vitamin K, so it’s not needed to take Vitamin K daily. If you are taking anti-coagulant (to prevent blood clotting) medication, consult your medical practitioner before taking a Vitamin K supplement.

Function

It is necessary for normal blood clotting and energy metabolism. It helps keep bones and teeth healthy since it plays an integral part in protein production by the body. K1 and K2 are both natural and can be created from the intestinal flora. K3 is synthetic.  For more info: FDA.Gov

Vitamin deficiency

Increased tendency to bleed, nosebleed

Food sources

Dark green leafy vegetables, spinach, broccoli, cabbage, liver, potatoes, cereals and yogurt

Examples of therapeutic usage (not always proven effective or safe)

It may improve bone strength in individuals with osteoporosis. Clinical studies in Japan suggest that menatetrenone (vitamin K2) reduces skeletal losses.

The vitamin may also alleviate nausea and vomiting during pregnancy. Women with heavy blood loss during menstruation may be helped. It can also reduce calcium loss in postmenopausal women.

Toxic dose – symptoms

Toxicity does not easily occur with normal dietary intake of this vitamin, but can happen if synthetic compound vitamin K3 is taken. High to toxic uptake in the synthetic form can cause flushing and sweating. Jaundice and anemia may also develop.

Vitamin K is fat soluble. This means that the body will not be able to get rid of the excess through urine, like water soluble vitamins. Because fat-soluble vitamins are stored for long periods, they generally pose a greater risk for toxicity than water-soluble vitamins when consumed in excess.  This applies if you take high doses of vitamin supplements. Eating a normal and well-balanced diet will not lead to toxicity in otherwise healthy individuals.

AIs (Adequate Intakes)

If you are taking anti-coagulant (to prevent blood clotting) medication, consult your medical practitioner before taking a Vitamin K supplement.

Infants 0-6 months 7-12 months	Micrograms per Day 2.0 2.5
Children 1-3 years 4-8 years	Micrograms per Day 30 55
Males 9-13 years 14-18 years 19-30 years 31-50 years 50-70 years > 70 years	- 60 75 120 120 120 120
Females 9-13 years 14-18 years 19-30 years 31-50 years 50-70 years > 70 years	- 60 75 90 90 90 90
Pregnancy < 19 years 19-30 years 31-50 years	- 75 90 90
Lactation < 19 years 19-30 years 31-50 years	- 75 90 90

Source: USDA Dietary Reference Intakes