Vitamin K Cautions
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Certain people should not take vitamin K supplements at all:
- People with a G6PD deficiency (a metabolic disorder)
- People with liver disease
Other people should seek medical advice before taking vitamin K supplements:
- People that are about to have surgery
- People that are about to have dental treatment
- People taking any medications
- People with cystic fibrosis
- People with severe diarrhoea that occurs for a long time
- People with severe gastrointestinal problems
- Women that are pregnant or breastfeeding
Certain people should not take vitamin K supplements, while other groups of people should seek medical advice about supplementation
Toxic Levels of Vitamin K
Vitamin K can be toxic at doses greater than 100mcg per day when the synthetic form of vitamin K is taken K3 - menadione.
Overdosage and Toxicity Symptoms
Toxicity of the synthetic form of vitamin K, K3 - menadione can cause the following toxicity symptoms:
- Anaemia
- Flushing
- Gastrointestinal pains
- Impaired liver function
- Itchy skin* (seek emergency treatment for this symptom)
- Jaundice
- Redness, pain or swelling at injection point
- Sweating
People experiencing any of the above toxicity symptoms should discontinue their vitamin K supplements and seek medical advice.
Overdosage and toxicity is more likely to occur from taking too many supplements, whereas dietary intake of vitamin K is highly unlikely to cause overdosage.
When infants and newborns are given too much vitamin K, it could present with the following toxicity symptoms:
- Haemolytic anaemia
- Hyperbilirubin (high amounts of bilirubin in the blood)
If either of these two symptoms above occur in newborns or infants, seek immediate emergency treatment.