Vitamin K toxicity

1. Vitamin K toxicity
Domina Petric, MD

2. Vitamin K toxicity
Phylloquinone exhibits no adverse
effects when administered in
massive doses by any route.
The menaquinones are similarly
thought to have negligible toxicity.

3. Vitamin K toxicity
• Menadione can be toxic.
• At high doses, it can produce
hemolytic anemia,
hyperbilirubinemia
and severe jaundice.

4. Vitamin K toxicity
• Phylloquinone has replaced menadione
for the vitamin K prophylaxis of
neonates.
• The intoxicating doses of menadione
appear to be at least three orders of
magnitude above those levels required
for normal physiological function.
• At such high levels, menadione appears
to produce oxidative stress.

5. Vitamin K toxicity
• The vitamer menadione is undergoing
monovalent reduction to the semiquinone
radical.
• In the presence of O2 it is reoxidized to
the quinone, resulting in the formation of
the superoxide radical anion.
• High levels of menadione are known to
react with free sulfhydryl groups, thus
depleting reduced glutathione (GSH)
levels.

6. Literature
• Combs GF. The Vitamins. Fundamental Aspects in
Nutrition and Health. Elsevier Inc. 2008.