Ingredients / Vitamin K
Vitamin K
MODERATEVitamin6 min readVitamin K is essential for blood clotting and bone health, with strong evidence supporting its role in coagulation and moderate evidence for bone mineral density improvement.
Clinical Dose
45-90 mcg per day
Best Form
Look for: Look for a standardized Vitamin K form with transparent potency labeling.
How it works
Vitamin K functions as a cofactor for the enzyme gamma-glutamyl carboxylase, which modifies certain proteins required for blood clotting. It also activates osteocalcin, a protein involved in bone mineralization. The exact mechanism by which it influences bone health is still being studied.
Who should take it
Individuals with osteoporosis or those at risk of vitamin K deficiency, such as people with malabsorption disorders.
Who should avoid it
Individuals on anticoagulant medications like warfarin, as vitamin K can interfere with these drugs.
Side effects
Generally well-tolerated; rare cases of allergic reactions have been reported.
Common forms
Standardized Vitamin K form
What the research says
Vitamin K is well-established in its role in blood coagulation, with recommended intakes effectively preventing deficiency-related bleeding disorders. Studies indicate doses of 45-90 mcg/day may improve bone mineral density, but results are mixed, and more research is needed to confirm optimal dosing for bone health. Some trials suggest benefits in cardiovascular health, but evidence is not yet conclusive.
Vitamin K supplementation and bone health in postmenopausal women
Supplementation with 90 mcg/day of vitamin K2 improved bone mineral density over two years.
View study
Food sources
Leafy green vegetables (e.g., spinach, kale), broccoli, and fermented foods like natto.
In depth: Vitamin K
Vitamin K is a fat-soluble vitamin crucial for blood coagulation and bone health, widely recognized for its role in preventing excessive bleeding and supporting skeletal integrity. In India, it is commonly used to address deficiencies, particularly among individuals with malabsorption issues or those on long-term antibiotics. Unlike its dietary sources, such as leafy greens (spinach, kale), and fermented foods (natto), supplemental Vitamin K is often used to achieve precise dosing for therapeutic benefits. Scientific research strongly supports its role in blood clotting, with the body requiring it to produce prothrombin, a key protein for coagulation. Additionally, there is moderate evidence suggesting that Vitamin K, particularly in the form of K2 (menaquinone), may improve bone mineral density by activating osteocalcin, a protein essential for bone mineralization. While some studies also hint at cardiovascular benefits, such as reducing arterial calcification, more research is needed to solidify these claims.
Key benefits
- ✓Blood Clotting: Essential for the synthesis of clotting factors, preventing excessive bleeding (Strong evidence).
- ✓Bone Health: Supports bone mineralization by activating osteocalcin, potentially improving bone mineral density (Moderate evidence).
- ✓Cardiovascular Health: May reduce arterial calcification, contributing to heart health (Emerging evidence).
- ✓Improved Insulin Sensitivity: Some studies suggest a role in glucose metabolism and insulin sensitivity (Limited evidence).
- ✓Antioxidant Properties: May help protect cells from oxidative stress, though evidence is preliminary (Limited evidence).
How to take it
The optimal dose range for Vitamin K is 45-90 mcg daily, which aligns with the recommended dietary allowance for adults. It is best taken with meals containing fats to enhance absorption, as it is a fat-soluble vitamin. There is no strict timing requirement, but consistency is key. Unlike some supplements, Vitamin K does not require cycling. When stacking, be cautious with Vitamin K antagonists like warfarin, as it can interfere with their efficacy. In the Indian market, typical supplements provide around 50-100 mcg per capsule, with prices ranging from ₹200 to ₹500 for a monthly supply. Given the widespread availability of Vitamin K-rich foods in Indian diets, supplementation is most beneficial for those with specific deficiencies or conditions affecting absorption.
Forms compared
Vitamin K1 (Phylloquinone)
Found abundantly in leafy greens, it primarily supports blood clotting. Common in multivitamins but less studied for bone health.
Vitamin K2 (Menaquinone)
More bioavailable and longer-lasting than K1, it is crucial for bone health. Often derived from fermented foods or synthesized for supplements.
MK-7 (Menaquinone-7)
A subtype of K2 with superior bioavailability and a longer half-life. Ideal for bone health but more expensive.
Safety & interactions
Vitamin K is generally safe for most people when taken within recommended doses. It has no known upper tolerable limit due to its low toxicity. However, individuals on anticoagulant medications like warfarin should consult a healthcare provider before supplementation, as Vitamin K can interfere with these drugs. It may also interact with some antibiotics, reducing their efficacy. For those with liver disease or conditions affecting fat absorption, caution is advised. Long-term use of Vitamin K supplements is considered safe, but it is always prudent to seek medical advice for prolonged supplementation. Pregnant and breastfeeding women should adhere to dietary recommendations unless otherwise advised by a healthcare provider.
India context
Vitamin K deficiency is relatively uncommon in India due to the rich dietary sources available, such as spinach, fenugreek, and other leafy greens. However, individuals with specific medical conditions or those following restrictive diets may be at risk. Regulatory standards for Vitamin K supplements are governed by the FSSAI, ensuring quality and safety. Common adulterants are rare, but consumers should be wary of products with unclear sourcing or lacking proper certifications. Quality supplements typically cost between ₹200 to ₹500 for a monthly supply. Vegetarians and those with limited access to green vegetables may benefit most from supplementation. Additionally, individuals with osteoporosis or cardiovascular concerns may find Vitamin K2 supplementation particularly advantageous.
Buying guide
When purchasing Vitamin K supplements, look for products that clearly state the form of Vitamin K (K1, K2, or MK-7) and the dosage per serving. Prefer supplements with certifications like FSSAI, NSF, or Informed Sport to ensure quality and purity. Avoid products with proprietary blends or those that do not disclose the full ingredient list. Be cautious of supplements containing artificial colours, flavours, or unnecessary fillers. Reading the ingredient list is crucial; ensure that the primary ingredient is Vitamin K and that the product does not contain excessive additives. For those focusing on bone health, MK-7 is preferable due to its superior bioavailability. Always check for third-party testing and transparency in sourcing.
Bottom line
Vitamin K is a worthwhile supplement for those with specific deficiencies or conditions affecting blood clotting or bone health. It is best for vegetarians, individuals with malabsorption issues, and those at risk of osteoporosis. For general health, dietary sources are usually sufficient, but supplementation with Vitamin K2 (MK-7) may offer additional benefits. Aim for a daily dose of 45-90 mcg, and choose a reputable brand with clear labeling and third-party certifications.
Frequently asked questions
Does Vitamin K cause any side effects?▾
Vitamin K is generally safe and well-tolerated. No common side effects are reported when taken at recommended doses.
When is the best time to take Vitamin K?▾
Vitamin K can be taken at any time, but it is best absorbed when taken with a meal containing fats.
Is Vitamin K safe for vegetarians?▾
Yes, Vitamin K supplements are suitable for vegetarians, as they are often derived from natural sources or synthesized in labs.
Can Vitamin K interact with medications?▾
Yes, Vitamin K can interfere with anticoagulant medications like warfarin. Consult a healthcare provider if you are on such drugs.
Is Vitamin K necessary if I eat leafy greens?▾
If you consume a diet rich in leafy greens and fermented foods, supplementation may not be necessary unless advised by a healthcare provider.
Products with Vitamin K
yourhappylife
Dose per serving: 22 mcg
7.8/10
Recommended
HK Vitals
Dose per serving: 55 mcg
7.2/10
Recommended
HK Vitals
Dose per serving: 55 mcg
7.1/10
Recommended
MYHERB
Dose per serving: 11.67 mcg
7.1/10
Recommended
Centrum
Dose per serving: 55 mcg
6.6/10
Recommended
OSOAA
Dose per serving: 12.4 mcg
6.5/10
Recommended
Dr. Vaidya's
Dose per serving: 90 mcg
6.4/10
Average
5.9/10
Average
FUELONE
Dose per serving: 55 mcg
5.9/10
Average
Optimum Nutrition
Dose per serving: 55 mcg
5.7/10
Average
Often stacked with Vitamin K
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