What Is Vitamin K1 (Phytonadione)? A Complete India Guide

India’s wellness market is growing fast, but with hundreds of products on Amazon.in and little standardisation, knowing what to actually buy is harder than it should be. This guide covers Vitamin K1 (Phytonadione) from first principles — what it is, how it works, who it suits, and how to use it safely.

What is Vitamin K1 (Phytonadione)?

Vitamin K1 (phylloquinone or phytonadione) is the primary dietary form of vitamin K, found in leafy green vegetables, plant oils and herbs. It is a fat-soluble vitamin essential as a cofactor for the enzyme gamma-glutamyl carboxylase, which activates vitamin K-dependent proteins (VKDPs) including clotting factors II, VII, IX and X, as well as matrix Gla protein (MGP) and osteocalcin. Unlike vitamin K2, K1 is primarily known for its coagulation role, though emerging evidence supports cardiovascular benefits.

It sits in the Vitamin category and is most relevant for people dealing with easy bruising, poor clotting, vascular calcification.

How does Vitamin K1 (Phytonadione) work?

As a cofactor for gamma-glutamyl carboxylase, K1 carboxylates glutamate residues on VKDPs, converting them to active forms. In coagulation, this produces functional clotting factors. In vascular tissue, K1 activates MGP, which inhibits calcium deposition in arteries and valves. A 3-year RCT found that 500 mcg/day K1 slowed coronary artery calcification progression by 6% in older adults with preexisting calcification. Higher dietary K1 intake (~120 mcg/day) is associated with lower carotid intima-media thickness and reduced cardiovascular events in older women.

It primarily acts on the blood, bones, blood vessels, heart valves, and effects are dose-dependent rather than immediate.

Who should consider Vitamin K1 (Phytonadione)?

Individuals seeking foundational vitamin K support for coagulation and bone health, those with low vegetable intake wanting K1 insurance, people interested in vascular calcification prevention, and those on vitamin D/calcium supplementation wanting to ensure proper calcium direction. Not a replacement for anticoagulant therapy management.

How much Vitamin K1 (Phytonadione) should you take?

A typical dose is 100 mcg, best taken with food, usually in the morning. Most people can expect noticeable effects within Immediate for coagulation; 4–8 weeks for vascular calcification markers. Consistency matters more than a single large dose.

Safety and who should avoid it

Individuals taking warfarin or vitamin K antagonists without medical supervision (K1 directly antagonises warfarin). Those with thrombophilia or hypercoagulable disorders. Not for people on therapeutic anticoagulation unless directed by their physician.

Side effects: Generally well-tolerated at 100–500 mcg/day. Very high doses may interfere with warfarin anticoagulation. Rare allergic reactions to injectable forms. No toxicity from oral doses within recommended ranges.

How to combine Vitamin K1 (Phytonadione)

Vitamin K1 (Phytonadione) is often layered into a broader protocol rather than taken alone. See the “Goes with” panel on its product page for evidence-aligned pairings, and introduce one new supplement at a time so you can attribute any change to the right product.

Frequently asked questions

Is Vitamin K1 (Phytonadione) available in India? Yes — it is sold on Amazon.in. Prioritise standardised, third-party-tested products.

How long until it works? Around Immediate for coagulation; 4–8 weeks for vascular calcification markers.

Can vegetarians take it? Check the label for a vegetable-cellulose capsule rather than gelatin.

Fitting Vitamin K1 (Phytonadione) into a daily routine

Adherence is easier when a supplement is anchored to an existing habit. Most people take Vitamin K1 (Phytonadione) in the morning, with food — pairing it with a daily meal or your morning routine makes it hard to forget. Keep the bottle where you will see it. Remember that Vitamin K1 (Phytonadione) is one input among many: sleep, diet, movement and stress management all act on the same blood, bones, blood vessels, heart valves and will amplify or blunt what any supplement can do.

What to realistically expect

Supplements rarely produce dramatic overnight change. With an evidence grade of B, Vitamin K1 (Phytonadione) is best understood as a steady, cumulative input rather than a quick fix. Expect gradual rather than sudden change over Immediate for coagulation; 4–8 weeks for vascular calcification markers, and measure against your own baseline. If after a fair trial at 100 mcg you notice nothing — subjectively or on relevant lab markers — that is useful information, and it is reasonable to stop.

Storage and stability

Heat and humidity are real considerations across much of India. Store Vitamin K1 (Phytonadione) in a cool, dry place away from direct sunlight, keep the bottle tightly closed, and avoid leaving it in a hot car or on a sunny kitchen shelf. A capsules kept in stable conditions retains potency far better than one repeatedly exposed to monsoon humidity. If your product arrives with a desiccant sachet, leave it in the bottle.

Where to buy Vitamin K1 (Phytonadione) in India

Vitamin K1 (Phytonadione) is available on Amazon.in. When buying, prioritise products that state the standardised active percentage, third-party testing (NSF, USP or Informed Sport), and a clear vegetarian-capsule declaration if that matters to you. Use the buy button on the Vitamin K1 (Phytonadione) page to see the current verified listing with the SacredBod tag.

This article is for informational purposes only. Consult a qualified healthcare provider before starting any supplement, especially if you take prescription medication or have a medical condition.