Best Vitamin K Supplements

Updated September 2019
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BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We may earn a commission if you purchase a product through our links.
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We buy all products with our own funds, and we never accept free products from manufacturers.
We may earn a commission if you purchase a product through our links.
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We purchase every product we review with our own funds — we never accept anything from product manufacturers.

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We purchase every product we review with our own funds — we never accept anything from product manufacturers.

Why trust BestReviews?
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We buy all products with our own funds, and we never accept free products from manufacturers.
We may earn a commission if you purchase a product through our links.
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We may earn a commission if you purchase a product through our links.
BestReviews spends thousands of hours researching, analyzing, and testing products to recommend the best picks for most consumers. We buy all products with our own funds, and we never accept free products from manufacturers.
We may earn a commission if you purchase a product through our links.

Buying guide for best vitamin K supplements

Last Updated September 2019

Vitamin K is one of four fat-soluble vitamins; the other three are vitamins A,E, and D. Vitamin K’s main role is to transport calcium to the bones in order to improve mineral density and prevent calcium accumulation and deadly blockages. This vitamin isn’t just a single nutrient: it’s a family of compounds, just like vitamin B.

When it comes to meeting your daily requirement of vitamin K, you may need the assistance of a vitamin K supplement, which provides nutrition where food sometimes can’t. Naturally, vitamin K1 is found in foods such as kale, broccoli, green beans, eggs, and strawberries. Vitamin K2 can be found mostly in fermented foods and animal products sourced from pasture-grown livestock. Since these are not often consumed regularly, especially for vegetarians and vegans, the need for a K2 supplement becomes more essential.

Navigating the world of vitamin K supplements can be difficult with such a multitude of choices available. Read on for information that will help you make the best choice.

Use vitamin K for added benefits like whiter teeth, a healthier dentist visit, and improved skin.

The body’s need for vitamin K

Vitamin K helps the body thrive by maintaining bone and blood vessel health. It also promotes the swift and healthy healing of wounds. While vitamin K is beneficial on its own, it works best when combined with vitamin D, which facilitates the proper absorption of calcium. Vitamin K2 directs calcium to the bones rather than the arteries, where calcification poses a risk.

Vitamin K supplementation is used by those who drink alcohol heavily, those with GI disorders that prevent vitamin K absorption, and those who take drugs that interfere with absorption, among others. Low levels of vitamin K can increase your risk of uncontrolled bleeding.

Types of vitamin K

K1 (phylloquinone) and K2 (menaquinone) are the main forms of vitamin K that are available in fat-soluble supplement form. The need for K2 vitamin supplements arises when individuals don’t consume a high volume of animal products or fermented food. The need for K1 becomes eminent if you can’t stand kale or spinach. K1 is responsible for blood coagulation and clotting, whereas K2 is used more prevalently for heart and bone disease prevention.

Within K2, there are vitamins MK4 and MK7. While MK4 usually comes from the tobacco plant and leaves the body relatively soon after entering it, MK7 is usually sourced from chickpeas, which offers more sustained protection. MK4 and MK7 are found in liquid or capsule form, often in soy-free, non-GMO, gluten-free, and vegetarian options.

There is a third type of vitamin K, known as K3, but since it is a synthetic version with potentially harmful health effects, we’ll be focusing on K1 and K2 here.

DID YOU KNOW?

It’s not unusual for newborn babies to be given a shot of vitamin K after birth, as infants are naturally born with lower levels of it, and it prevents internal bleeding.

Dosage

Vitamin K supplement dosage needs to be adjusted based on gender and age, as an excessively high dosage can be dangerous. Adult men require 120 micrograms, while adult women need 90 micrograms. Teens are advised to take 75 micrograms a day, while children between the ages of nine and 13 are limited to a daily intake of 60 micrograms. Those suffering from bleeding disorders like hypoprothrombinemia are generally advised to take between 2.5 and 25 mg of K1 but should consult their doctors before committing to any dose.

Side effects

While some individuals may require a K1 or K2 supplement, if you’re eating K2-rich foods and are otherwise healthy, the need may not arise. Side effects can occur, but they are rare. These include swelling or itching, dizziness, difficulty breathing, and increased risk of bleeding when combined with certain drugs or antibiotics.

CAUTION

While vitamin K1 and K2 are completely safe, vitamin K3 (or menadione) is a synthetic form of the vitamin that is considered toxic when consumed in high doses, potentially causing cytotoxicity in the liver, allergic reactions, and forms of anemia.

Additional ingredients

The following ingredients are included in some, but not all, vitamin K supplements.

Coconut oil or extra virgin olive oil: Vitamin K is fat-soluble, and these added oils may enhance its absorption.

Vitamin D: Since vitamin D and vitamin K work optimally in conjunction, they are often combined.

Maltodextrin: Maltodextrin is produced from starch and is used as a food additive. Although approved by the FDA, it is high on the glycemic index and not suitable for those who are sensitive to allergies.

Magnesium stearate: This is a commonly used additive in supplements, and in small amounts, it’s generally harmless. However, it is hydrophobic, which means it may slow the rate of absorption in your GI tract or have a laxative effect in large doses.

Vitamin K supplement prices

To make sure you’re optimizing your value, it’s a good idea to calculate exactly how many servings the bottle contains in the context of the total cost. The reason: when purchased in larger quantities, you may save a significant amount. For instance, a 90-capsule bottle may end up costing you 0.17 cents per pill, whereas a 180-capsule bottle may cost you 0.11 cents per pill. On average, a vitamin K supplement costs around 0.14 cents to 0.30 cents per pill, with D3-enhanced products potentially costing up to a dollar per pill.

Pay attention not just to price but also to what additives and additional ingredients are in any  supplement you’re considering. If the price is decent and competitive with other vitamin K supplements and the product contains vitamin D, you’re getting more value out of your purchase. Vitamin K supplements bolstered with vitamin D or high-end ingredients like coconut oil often cost more, but the investment may be worth it, depending on your goals.

As always, be sure to consult with your doctor before starting a new supplement regimen.

EXPERT TIP

Vitamin K can aid in lightening heavy menstrual periods without the usage of hormonal birth control, thanks to its coagulation properties. However, be sure to consult your doctor first.


Staff  | BestReviews

Tips

  • Consistency is key. Take your supplement daily with a meal for best results.

  • Always check the expiration date on your supplements. Make sure you’re only consuming healthy, non-expired ingredients that work to their maximum capabilities.

  • Check for ingredients which may conflict with your lifestyle or existing allergies. Some brands offer vegetarian, soy-free, or gluten-free options.

  • If you’re taking the drug Coumadin, which is used to slow blood clotting, consult your doctor before usage. A vitamin K supplement may decrease the effectiveness of this drug.

  • Try to combine your vitamin K supplement with a vitamin D supplement if you’re not taking a two-in-one combination already. They enhance each others’ functions.

Other products we considered

For those who prefer not to take their supplements in pill form, MaryRuth’s Organics MK7 Vitamin K2 drops offers an all-natural, organic alternative in the form of concentrated drops with a mild olive oil taste. Using the chickpea extract MK7, this vegan formula is plant-based, non-GMO, ketogenic, paleo, corn-free, soy-free, nut-free, and wheat-free. In other words, it’s suitable for many people with allergies.

Alternatively, we suggest Vitamin K Triple Play by Bronson. A crowd favorite, this supplement covers all three bases by combining K1, K2 MK7, and K2 MK4. Coming from a trusted and reputable company, these soft capsules are available in quantities of 90 and 180.

Vitamin K is absorbed best with healthy fats. For this reason, it is suggested that individuals consume veggies high in vitamin K while they are also consuming a fat — ideally a fermented one such as kefir yogurt.

FAQ

Q. Can too much vitamin K be harmful?
A.
If you have diabetes and are taking a K1 supplement, blood sugar levels need to be monitored closely. If you are receiving dialysis, excessively high doses of vitamin K may in fact worsen clotting issues.

Q. What are some symptoms of low vitamin K?
A.
If you have a vitamin K deficiency, you might bruise easily, see blood in your urine or stool, or have unusually heavy menstrual periods.

Q. Which drugs interfere with the effects of a vitamin K supplement?
A.
Drugs for cancer, high cholesterol, and seizures may interfere with vitamin K supplementation, as well as antacids, blood thinners, aspirin, and certain antibiotics.

The team that worked on this review
  • Alvina
    Alvina
    Photographer
  • Amos
    Amos
    Director of Photography
  • Branson
    Branson
    Videographer
  • Ciera
    Ciera
    Production Assistant
  • Devangana
    Devangana
    Web Producer
  • Eliza
    Eliza
    Production Manager
  • Katie
    Katie
    Editorial Director
  • Melinda
    Melinda
    Web Producer
  • Melissa
    Melissa
    Senior Editor
  • Steph
    Steph
    Web Producer

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