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Vitamin K Excess & Liver Problems

Vitamin K is a nutrient necessary for much of your body to work properly, including the blood and the bones. However, some types of vitamin K can cause damage to the liver and other body systems. One type--synthetic vitamin K--is even banned by the Food and Drug Administration.

  1. Natural Vitamin K

    • Naturally-occurring vitamin K has no set tolerable upper limit. Unlike most fat-soluble vitamins, excess vitamin K is not stored in the liver and has never been shown to produce toxicity symptoms. It is available in many food sources, especially green, leafy vegetables and beef organ meats (liver, kidney).

    Synthetic Vitamin K

    • Synthetic vitamin K is manufactured in laboratories and is not a pure form of the vitamin. It often causes toxic symptoms in the liver and has been banned by the FDA as an over-the-counter supplement.

    What's the Difference?

    • Vitamin K1, phylloquinone, is found in natural food sources. Vitamin K2, menaquinone, is synthesized and absorbed by bacteria in the intestines. This is also a safe, natural form. Synthetic vitamin K3, also known as menadione, was originally used to treat vitamin K deficiency, especially in newborns, but has been proved to cause severe damage to the liver and other body systems.

    Symptoms of Toxicity

    • Toxicity caused by an overdose of synthetic vitamin K generally starts with jaundice, a symptom of liver cell necrosis (cell death) and a loss of liver function. It also produces hemolytic anemia, the premature breakdown of blood cells and the destruction of needed antioxidants in the body.

    Recommended Dosage

    • Although natural vitamin K has never been shown to produce toxicity, it still has an RDA (recommended daily amount). For adult men it's 80 micrograms, adult women 65 mcg, children 7 to 10 years 30 mcg and infants 10 mcg. Synthetic vitamin K, menadione, should be avoided altogether.

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