Vitamin K

Vitamin K is a fat soluble vitamin.

RDA (Recommended Dietary Allowance):

• Adults (19+ years):
  • Men: 120 mcg/day
  • Women: 90 mcg/day
• Pregnant and breastfeeding women: 90 mcg/day

ODA (Optimal Daily Allowance):

• 90-300 mcg/day (depending on individual health goals and bone health requirements)

Found in:

• Green leafy vegetables (kale, spinach, collard greens)
• Broccoli and Brussels sprouts
• Fermented foods (natto, sauerkraut)
• Fish, meat, and eggs (small amounts)
• Dairy products
• Vegetable oils (soybean and canola oils)

Helps with:

• Blood clotting (essential for synthesis of clotting factors in the liver)
• Maintaining bone health by regulating calcium binding in bones
• Supporting cardiovascular health by preventing arterial calcification
• Promoting wound healing

Insufficient doses:

• Symptoms of deficiency (rare in healthy adults):
  • Easy bruising and bleeding (e.g., nosebleeds, heavy menstrual bleeding, bleeding gums)
  • Blood in urine or stool
  • Weakened bones and increased risk of fractures
• Deficiency is more common in:
  • Newborns (due to low vitamin K stores at birth)
  • Individuals with fat malabsorption disorders (e.g., celiac disease, Crohn’s disease)
  • Long-term use of antibiotics (which disrupt gut bacteria that produce this vitamin )

Excessive doses:

• No established upper limit for vitamin K from food or supplements
• Generally considered safe, but excessive synthetic vitamin K3 (menadione) can cause:
  • Liver damage
  • Jaundice
  • Hemolytic anemia (especially in newborns)

Interactions:

• Synergy:
  • Works with vitamin D to regulate calcium balance and promote bone health.
  • Enhances the effects of magnesium on bone density.
  • Collaborates with vitamin E to protect against oxidative damage while maintaining blood clotting balance.
• Antagonistic interactions:
  • High doses of vitamin E can interfere with vitamin K’s clotting functions.
  • Anticoagulant medications (e.g., warfarin) can be affected by vitamin K intake, requiring consistent dietary levels.
  • Excessive vitamin A intake may counteract the effects of vitamin K on bone health.