Are unique set of  vitamins that are lipophilic and hydrophobic

Chemically this set of vitamins have a methylated naphthoquinone ring and a side chain

Types:

Vitamin K₁ - phylloquinone

Vitamin K₂ - menaquinone – produce by bacteria in the intestines

Vitamin K₃ - synthetic form – used in pet food industry

Vitamin K₄ - synthetic form

Vitamin K₅ - synthetic form – used to stop fungal growth

Sources:

   -    Spinach 
   -    Cauliflower
   -    Broccoli
   -    Brussel sprouts
   -    Avocado
   -    others

Function:

   -    Necessary in Blood Coagulation
   -    Important in bone metabolism
   -    Co-enzyme
   -    Cofactor
   -    others

Deficiency

   -    Bleeding
   -    Anemia
   -    Bruising
   -    Newborns are at risk
   -    Those with damaged liver are at risk

Toxicity – is rather rare for most forms