What are the guidelines for taking Vitamin K (Vit K) 200 micrograms (mcg) orally?

Vitamin K 200 mcg Oral Use

Vitamin K 200 mcg orally is NOT a standard therapeutic dose for any established clinical indication. This dose is far below recommended treatment doses for vitamin K deficiency or reversal of anticoagulation, and routine supplementation is not recommended for most patients.

Standard Therapeutic Dosing Context

For Vitamin K Deficiency Treatment

• Oral vitamin K deficiency requires 1,000-2,000 mcg (1-2 mg) daily for treatment, which is 5-10 times higher than 200 mcg 1
• For severe deficiency with coagulopathy or osteoporosis, doses of 10,000-25,000 IU (approximately 5-12.5 mg) daily for 1-2 weeks are recommended 1
• The 200 mcg dose falls far short of therapeutic requirements for documented deficiency

For Anticoagulation Reversal

• For INR 5.0-9.0 with high bleeding risk: 1,000-2,500 mcg (1-2.5 mg) oral vitamin K 2, 3
• For INR >10 without bleeding: 2,500-5,000 mcg (2.5-5 mg) oral vitamin K 2, 3
• The American Society of Hematology recommends 5,000 mcg (5 mg) for INR >10 3
• A 200 mcg dose is 5-25 times lower than recommended reversal doses and would be clinically ineffective

Routine Supplementation

• The American College of Chest Physicians suggests AGAINST routine vitamin K supplementation in patients on vitamin K antagonists (Grade 2C) 1
• Routine supplementation can interfere with anticoagulation stability and is not recommended for most patients 1

Dietary Reference Intake

• The Institute of Medicine recommends 90 mcg/day for females and 120 mcg/day for males as adequate intake from dietary sources 4
• Green leafy vegetables constitute the major dietary source 5
• A 200 mcg supplement slightly exceeds daily requirements but has no established therapeutic benefit

Clinical Scenarios Where 200 mcg Is Inappropriate

Patients on Warfarin/VKAs

• Avoid routine vitamin K supplementation as it destabilizes INR control 1
• Even small supplemental doses can reduce anticoagulant effectiveness
• If vitamin K is needed for elevated INR, therapeutic doses (1-5 mg) are required, not 200 mcg 2, 3

Documented Vitamin K Deficiency

• 200 mcg is inadequate for treating deficiency 1
• Therapeutic doses start at 1-2 mg daily minimum 1
• For fat-soluble vitamin malabsorption (post-bariatric surgery), even higher doses or parenteral administration may be needed 1

Potential Limited Use Case

Bone Health Supplementation (Controversial)

• Some research suggests vitamin K may improve bone mineral density when combined with vitamin D 4
• However, most intervention studies used vitamin K2 at much higher doses (not 200 mcg of K1) 4
• This indication lacks strong guideline support and should not be the primary rationale for 200 mcg supplementation

Key Pitfalls to Avoid

• Do not use 200 mcg vitamin K to treat elevated INR - it is grossly insufficient and delays appropriate management 2, 3
• Do not routinely supplement patients on warfarin - this interferes with anticoagulation control 1
• Do not use 200 mcg to treat documented vitamin K deficiency - therapeutic doses are 5-10 times higher 1
• Do not confuse dietary adequate intake (90-120 mcg) with therapeutic dosing (1,000-5,000 mcg) 4, 2

Practical Recommendation

For most clinical scenarios requiring vitamin K intervention, 200 mcg is an inappropriate dose. If vitamin K supplementation is being considered:

• For anticoagulation reversal: Use 1-5 mg based on INR level and bleeding risk 2, 3
• For documented deficiency: Use 1-2 mg daily minimum, up to 10-25 mg for severe cases 1
• For patients on warfarin: Avoid routine supplementation entirely 1
• For general health: Adequate dietary intake (90-120 mcg) from food sources is preferred over supplementation 4, 5