Vitamin K is a fat-soluble vitamin, essential for several bodily functions:

1. Blood Clotting: Vitamin K is crucial for synthesizing proteins that the body needs for blood clotting¹²³⁴. Without sufficient vitamin K, the body cannot produce clotting factors, increasing the risk of uncontrolled bleeding.

2. Bone Health: It helps in the formation of strong bones by assisting in the creation of osteocalcin, a protein that binds calcium to bones³⁴⁵.

3. Heart Health: Vitamin K may contribute to heart health by preventing vascular calcification, thus potentially reducing the risk of cardiovascular diseases⁵.

Sources of Vitamin K

Vitamin K is found in two primary forms:

• Phylloquinone (Vitamin K1): Found predominantly in green leafy vegetables like kale, spinach, broccoli, and Brussels sprouts¹⁶⁷⁴.
• Menaquinone (Vitamin K2): Present in fermented foods such as natto, cheese, and is also produced by bacteria in the human gut¹⁴.

Recommended Intake

The recommended dietary intake for vitamin K varies by age and sex²:

• Infants: 2.0-2.5 micrograms per day (mcg/day)
• Children: 30-60 mcg/day depending on age
• Adolescents and Adults:
  • Males: 120 mcg/day
  • Females: 90 mcg/day

Deficiency and Risks

Vitamin K deficiency is rare but can lead to increased bleeding and bruising. It can occur due to poor absorption or long-term use of antibiotics, which reduce gut microbiota responsible for its production¹³.

Interactions with Medication

Individuals on anticoagulants like warfarin need to monitor their vitamin K intake closely as it can affect the medication's efficacy⁴. Consistent intake is vital to avoid fluctuations in prothrombin time (a measure of blood clotting).

For further detailed reading, see resources like MedlinePlus, NHS, and the Office of Dietary Supplements.

Footnotes

1. MedlinePlus - Vitamin K ↩ ↩² ↩³ ↩⁴

2. Office of Dietary Supplements - Vitamin K ↩ ↩²

3. NHS - Vitamin K ↩ ↩² ↩³

4. PMC - Role in aging and diseases ↩ ↩² ↩³ ↩⁴ ↩⁵

5. PMC - Therapeutic use ↩ ↩²

6. The Nutrition Source | Harvard ↩

7. NCBI Bookshelf - Vitamin K ↩