Puritan's Pride Premium Vitamin K 100mcg, 100 Tablets Review
Puritan's Pride Vitamin K 100 mcg (Item #003070) is a dietary supplement offered in a bottle size of 100 tablets, providing a potency of 100 mcg of Vitamin K per serving. According to the product description, Vitamin K is an essential nutrient that is necessary for the formation of prothrombin, a critical protein which is required by the body for normal blood clotting. Furthermore, Vitamin K is highlighted as a great companion nutrient to take alongside Calcium and Vitamin D supplements to support overall wellness and bone health. Each single-tablet serving delivers 100 mcg of Vitamin K in the form of Phytonadione, which equates to 83% of the recommended Daily Value. For optimal use, the directions state that adults should take one (1) tablet daily, preferably with a meal. The tablet formulation is crafted using specific other ingredients, which include Dicalcium Phosphate, Vegetable Cellulose, Vegetable Stearic Acid, and Vegetable Magnesium Stearate. This supplement is certified Gluten Free, Vegetarian, and Non-GMO. In addition, the formula is free from common allergens and additives: it contains No Artificial Color, Flavor, or Sweetener, No Preservatives, No Sugar, No Starch, No Milk, No Lactose, No Soy, No Gluten, No Wheat, No Yeast, No Fish, and is completely Sodium Free. For safety, the product label advises that if you are pregnant, nursing, taking any medications, or have any medical condition, you should consult your doctor before use. Users should discontinue use and consult a doctor if any adverse reactions occur, keep the bottle out of reach of children, store it at room temperature, and not use the product if the seal under the cap is broken or missing. For more than 50 years, Puritan's Pride has helped families achieve a lifestyle of wellness by making vitamins and supplements with care from the highest quality ingredients, which are tested or inspected as many as 15 times throughout the manufacturing process so customers can shop with confidence.
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Study, Trial or Testing Result Summary
Members Only50 human studies · 23 improved
This product contains vitamin K1 (phytonadione), 100 micrograms per tablet, or 200 micrograms at the two tablets a day members are told to take. Most of the positive bone research tested a different form, vitamin K2. A review of 16 trials in 6,425 women after menopause found vitamin K2 improved lower spine bone density, with no clear drop in fractures and no extra side effects [1]. A three year trial in 244 women found 180 micrograms a day of vitamin K2 slowed bone loss in the spine and hip [2]. A review of eight trials found vitamin K taken with vitamin D raised total bone density [3]. Another review of 43 trials found vitamin K raised a blood marker of bone building [4]. Trials that tested vitamin K1 itself were less encouraging. In 452 older adults, 500 micrograms a day of vitamin K1 for three years did not change bone density [5]. In 440 women with low bone density, 5 milligrams a day of vitamin K1 did not change bone density, though fewer women had fractures, a small secondary finding [6]. Both of those trials used more vitamin K1 than this product provides. Animal and cell studies are never counted.
See all 50 studies →Hide the studies
- In five observational studies of 80,982 people, those with the highest dietary vitamin K intake had about 22% lower fracture risk than those with the lowest.Vitamin K intake and the risk of fractures: A meta-analysis.
- Across 16 trials of 6,425 postmenopausal women, vitamin K2 improved lower spine bone density and lowered undercarboxylated osteocalcin, with no overall fracture reduction unless one outlier study was excluded and no extra side effects.Efficacy of vitamin K2 in the prevention and treatment of postmenopausal osteoporosis: A systematic review and meta-anal…
- In 43 trials of 5,184 postmenopausal women, vitamin K gave the largest rise in a bone formation marker (bone alkaline phosphatase), and vitamin K with vitamin D most increased other bone formation markers.Effects of dietary supplements on bone turnover markers in women after menopause: a network meta-analysis.
- In eight trials of 971 people, vitamin K combined with vitamin D increased total bone density and lowered undercarboxylated osteocalcin, with doses under 500 mcg per day working well.The combination effect of vitamin K and vitamin D on human bone quality: a meta-analysis of randomized controlled trials…
- In three small trials of 70 people with cystic fibrosis, it is very uncertain whether vitamin K changes bone density, though undercarboxylated osteocalcin fell.Vitamin K supplementation for cystic fibrosis.
- A review of Japanese trials reports vitamin K2 and K1 were linked to maintained or higher bone density and fewer fractures, though a larger trial with fractures as the main outcome is still needed.[Vitamin K2].
- In a review of seven trials of at least two years in postmenopausal women, high-dose vitamin K1 and K2 improved femoral neck bone strength indices and reduced clinical fractures despite little change in bone density.High-dose vitamin K supplementation reduces fracture incidence in postmenopausal women: a review of the literature.
- In five trials in postmenopausal women, vitamin K1 cut clinical fractures versus placebo in one good trial, while the K2 trials were poorly reported with mixed results and the larger one showed no reduced vertebral fractures.Vitamin K to prevent fractures in older women: systematic review and economic evaluation.
- This review looked at vitamin K levels, diet and supplements in relation to bone health, but the abstract says findings across studies were conflicting and unclear.Vitamin K and osteoporosis: Myth or reality?
- This review of ten studies on vitamin K for osteoporosis in postmenopausal women did not report clear results in its abstract, so the size of any benefit is not stated.The Anti-osteoporosis Effects of Vitamin K in Postmenopausal Women.
- In 452 men and women aged 60-80 who also took calcium and vitamin D, 500 micrograms a day of vitamin K1 for 3 years did not change bone density at the hip, spine or whole body compared with no vitamin K1.Effect of vitamin K supplementation on bone loss in elderly men and women.
- In 440 postmenopausal women with low bone density, 5 mg a day of vitamin K1 for 2 to 4 years did not change bone density compared with placebo, though fewer women had clinical fractures (9 versus 20), a small secondary finding.Vitamin K supplementation in postmenopausal women with osteopenia (ECKO trial): a randomized controlled trial.
- In 379 healthy older adults, 500 mcg per day of phylloquinone for 3 years did not change inflammatory markers or bone density changes compared with no supplement.Vitamin K, circulating cytokines, and bone mineral density in older men and women.
- In 325 postmenopausal women, 45 mg per day of menatetrenone for 3 years increased bone mineral content and femoral neck width compared with placebo and kept hip bone strength unchanged, though overall bone density was not changed.Vitamin K2 supplementation improves hip bone geometry and bone strength indices in postmenopausal women.
- In 244 healthy postmenopausal women, 180 mcg of MK-7 daily for 3 years slowed the age-related loss of bone mineral density in the lumbar spine and femoral neck compared with placebo.Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women.
- In 219 healthy young and older adults, 1000 mcg per day of phylloquinone for 2 weeks raised vitamin K levels about tenfold and lowered undercarboxylated osteocalcin, a vitamin K status marker, but did not change other bone turnover markers.Vitamin K supplementation reduces serum concentrations of under-gamma-carboxylated osteocalcin in healthy young and elde…
- In 181 postmenopausal women aged 50 to 60, 1 mg per day of vitamin K1 added to minerals and vitamin D for 3 years reduced femoral neck bone loss compared with placebo, but did not change lumbar spine bone loss.Vitamin K1 supplementation retards bone loss in postmenopausal women between 50 and 60 years of age.
- In a 12-month placebo-controlled trial of 148 postmenopausal women, 375 mcg of vitamin K2 (MK-7) daily cut undercarboxylated osteocalcin, a bone marker, by about 70% compared with a small change on placebo.Vitamin K2 (menaquinone-7) increases plasma adiponectin but does not affect insulin sensitivity in postmenopausal women:…
- In a 3-year placebo-controlled trial of 142 postmenopausal women with low bone mass, 375 mcg daily of menaquinone-7 added to calcium and vitamin D raised carboxylated osteocalcin but did not change bone mineral density or bone structure compared with placebo.The effect of vitamin MK-7 on bone mineral density and microarchitecture in postmenopausal women with osteopenia, a 3-ye…
- In 123 people on dialysis, 360 mcg of MK-7 daily for 2 years prevented lumbar spine bone loss compared with placebo but sped up bone loss in the distal radius, so the authors do not recommend it for bone protection.Vitamin K supplementation and bone mineral density in dialysis: results of the double-blind, randomized, placebo-control…
- In a placebo-controlled trial of 120 adults, 100 mcg daily of menaquinone-7 for 12 weeks improved the activation of the bone protein osteocalcin compared with placebo, and a dose-finding trial suggested 100 mcg or more is needed.Low-Dose Daily Intake of Vitamin K(2) (Menaquinone-7) Improves Osteocalcin γ-Carboxylation: A Double-Blind, Randomized C…
- Female endurance athletes who took vitamin K1 or placebo for two years lost similar amounts of hip bone density, and vitamin K did not prevent the bone loss.Factors affecting bone loss in female endurance athletes: a two-year follow-up study.
- In 110 healthy children and adults, MK-7 supplements improved vitamin K status most in people who were most deficient, and adults over 40 may benefit, though bone outcomes were not directly measured.Vitamin K status in healthy volunteers.
- In 105 postmenopausal women with osteoporosis taking meds, 1 mg of vitamin K1 daily for 18 months did not change bone density or bone turnover compared with placebo, though it had a small effect on some hip shape measures.Read the study on PubMed (37338608) →
- In a 1-year randomized double-blind trial of 94 lung and heart transplant recipients, 180 mcg daily of menaquinone-7 gave a favorable change in lumbar spine bone density compared with placebo, though the difference was borderline in the overall group.Dietary vitamin K2 supplement improves bone status after lung and heart transplantation.
- Adults with Crohn's disease who took 1000 micrograms of vitamin K1 daily with calcium and vitamin D for a year had no better bone turnover or bone density than those on placebo, apart from a small gain in forearm bone mass.Effect of phylloquinone (vitamin K1) supplementation for 12 months on the indices of vitamin K status and bone health in…
- In elderly hip fracture patients over 4 months, vitamin K1, calcium and vitamin D raised blood vitamin K1 levels but did not change bone turnover markers compared with usual care.Effects of nutritional intervention upon bone turnover in elderly hip fracture patients. Randomized controlled trial.
- In 68 people with type 2 diabetes and heart disease, 360 mcg of vitamin K2 daily for 6 months did not slow vertebral bone density loss compared with placebo.Six months vitamin K treatment does not affect systemic arterial calcification or bone mineral density in diabetes melli…
- In 60 adults with type 2 diabetes, 200 mcg per day of menaquinone-7 for 12 weeks did not change body composition, including bone mass, compared with placebo.The effect of menaquinone-7 supplementation on dp-ucMGP, PIVKAII, inflammatory markers, and body composition in type 2 d…
- In a 2-year placebo-controlled trial of 40 children with galactosemia, daily vitamin K1 with calcium and vitamin D3 raised lumbar spine bone mineral content, and this gain was seen only in the younger, prepubertal children.Effect of calcium, vitamins K1 and D3 on bone in galactosemia.
- In a 14-week placebo-controlled pilot of 33 postmenopausal women, a combination including 1000 mcg of vitamin K1 per day lowered serum osteocalcin, a bone turnover marker, by about 31% while placebo raised it by 19%.Hop rho iso-alpha acids, berberine, vitamin D3 and vitamin K1 favorably impact biomarkers of bone turnover in postmenopa…
- Postmenopausal women who took 200 or 500 micrograms of vitamin K1 daily for six weeks improved their vitamin K levels, but their bone turnover markers did not change compared with placebo.Effect of phylloquinone supplementation on biochemical markers of vitamin K status and bone turnover in postmenopausal w…
- Postmenopausal women who ate 450 micrograms of vitamin K1 daily for a few weeks had a modest drop in a bone breakdown marker, but bone formation and mineral handling did not change.Dietary phylloquinone depletion and repletion in postmenopausal women: effects on bone and mineral metabolism.
- In 20 postmenopausal women with osteoporosis and wrist fractures, two weeks of vitamin K supplements corrected a defect in how bone protein osteocalcin was activated, and the benefit was still detectable four weeks later.Carboxylation of osteocalcin in post-menopausal osteoporotic women following vitamin K and D supplementation.
- In a one-year randomized pilot of 16 a med-treated patients, adding vitamin K2 to risedronate gave no extra reduction in bone turnover markers beyond risedronate alone.Read the study on PubMed (20190467) →
- In 15 young adults in a crossover study, hydrogenated vitamin K (dihydrophylloquinone) at 200 mcg per day for 10 days was less absorbed than regular phylloquinone and had no measurable effect on markers of bone formation or breakdown.Effects of a hydrogenated form of vitamin K on bone formation and resorption.
- Elderly Chilean adults with thin hip bones who took a multi-nutrient supplement containing 60 micrograms of vitamin K daily for a year saw no change in bone density compared with the usual supplement, although their vitamin D rose and some bone turnover markers fell.Effect of a nutritional supplementation on bone health in Chilean elderly subjects with femoral osteoporosis.
- In a 6-month randomized trial of Indian premenopausal women aged 25 to 44, a daily protein beverage fortified with 55 mcg of vitamin K, plus calcium and vitamin D, lowered bone turnover markers compared with a non-fortified placebo drink.Randomised Controlled Trial of Nutritional Supplement on Bone Turnover Markers in Indian Premenopausal Women.
- Over 2 years, young Chinese women aged 20 to 35 who drank milk powder with 80 mcg of vitamin K1 and 1000 mg calcium did not gain more bone density than the control group, which received nothing.Milk supplementation and bone health in young adult chinese women.
- Elderly women with Parkinson's disease and low vitamin D who took 45 mg of vitamin K2 daily for a year had bone density in the hand that rose slightly, while untreated women lost bone, and fewer of the treated women broke a hip; this paper has been retracted.Amelioration of osteoporosis by menatetrenone in elderly female Parkinson's disease patients with vitamin D deficiency.
- In 108 stroke patients with vitamin D and K deficiency, 45 mg of menatetrenone daily for 12 months raised bone density on the paralyzed side by 4.3% while untreated patients lost 4.7%.Menatetrenone ameliorates osteopenia in disuse-affected limbs of vitamin D- and K-deficient stroke patients.
- In healthy volunteers, menaquinone-7 was absorbed well and fully activated osteocalcin, a bone protein, more completely than synthetic vitamin K1, but no bone density or fracture outcome was measured.Vitamin K-containing dietary supplements: comparison of synthetic vitamin K1 and natto-derived menaquinone-7.
- In healthy women given 1 mg of vitamin K daily, bone-related blood markers changed in some women, and in women who lost the most urinary calcium, calcium loss fell by about 30%; the abstract was truncated and the results are mixed.Vitamin K-induced changes in markers for osteoblast activity and urinary calcium loss.
- In 109 postmenopausal women with osteoporosis, 45 mg of menatetrenone daily for 6 months raised active bone-building osteocalcin compared with calcium aspartate, but urinary bone-breakdown marker NTX also rose, so the effect on bone turnover was mixed.Short-term menatetrenone therapy increases gamma-carboxylation of osteocalcin with a moderate increase of bone turnover …
- Postmenopausal women with osteoporotic fractures who took 5 mg of vitamin K2 daily cut their undercarboxylated osteocalcin, a marker of low vitamin K, by about three-quarters, and 45 mg gave no further gain.Maximal dose-response of vitamin-K2 (menaquinone-4) on undercarboxylated osteocalcin in women with osteoporosis.
- Patients with severe motor and intellectual disabilities who received vitamin K1 food-based therapy for three months had better vitamin K status, but bone formation and breakdown markers both rose, so the bone effect is unclear.Nutritional Therapy with Vitamin K1 Is Effective in the Improvement of Vitamin K Status and Bone Turnover Markers in Pat…
- In 8 female elite athletes, one month of 10 mg daily vitamin K raised bone-building markers by about 15-20% and lowered bone-breakdown markers by about 20-25%, with no placebo group for comparison.Improved bone metabolism in female elite athletes after vitamin K supplementation.
- In a case-control study of 99 people with Crohn's disease and 56 controls, low vitamin K intake was more common in Crohn's patients with metabolic bone disease, but this study did not test giving vitamin K.Risk factors for metabolic bone disease in Crohn's disease patients.
- In postmenopausal women, vitamin K lowered urinary calcium loss in a subgroup with high calcium loss, while long-term blood-thinning treatment that blocks vitamin K was linked to more calcium loss in young men than in untreated controls.Read the study on PubMed (8435316) →
- In children with cystic fibrosis, higher vitamin K intake was linked to bone markers, suggesting possible bone health benefits, though the study details were limited.Vitamin K supplementation in cystic fibrosis.
Review Totals and Summary
Members Only6,676 reviews · 93% positive
This Puritan's Pride Premium Vitamin K product, available as 100mcg tablets, has received approximately 6676 ratings across various stores, with a strong majority of customers expressing satisfaction. About 75% of reviews with star ratings give it 4 or 5 stars, indicating a generally positive reception. **What it did for them** Many customers report positive outcomes from taking these tablets. A common benefit mentioned is its effectiveness in "bruise prevention," with one user noting it "helps me with the bruising on my arms and hands." Other reviewers simply state it is a "good product" or "great product," expressing general satisfaction with its performance and progress, with one user noting that doctor visits showed "it's working." Some customers also use it "in conjunction with my vitamin D" as part of their supplement regimen. **Complaints** While most feedback is positive, some concerns were raised. A recurring complaint from a few customers is about product availability, with one reviewer lamenting, "why don't you carry it anymore." Another significant complaint relates to the type of Vitamin K. One customer, seeking Vitamin K for bone health, felt this product was the "wrong type for bones," believing it was "more for blood clotting" and therefore unsuitable for their specific needs. **Pill Characteristics** The tablets are described as "small white vitamin k" pills. One customer found them "so tiny hard to find it in my mouth," indicating that their small size can be a drawback for some users. This summary focuses solely on the tablet form of the product, excluding reviews for other forms like capsules or gummies. **Value for Money** The product is frequently praised for its affordability. Many customers consider it a "great price," especially when purchased on sale. One reviewer highlighted an "exceptional deal" when buying it at a significant discount. This suggests that the product offers good value, particularly for budget-conscious buyers. **Who it seems to suit and who it did not** This Vitamin K supplement appears to suit individuals looking for general Vitamin K benefits, including bruise prevention, and those who are long-time users of Puritan's Pride supplements. It is also suitable for those who appreciate a small, easy-to-swallow tablet and good value. However, it may not be ideal for customers who find very small pills difficult to handle. Crucially, it may not be suitable for those specifically seeking a particular type of Vitamin K for bone health, as one customer perceived this product to be more aligned with blood clotting benefits and found it unsuitable for their needs.
Biohacker Summary
Members Only7 of 10 recommend it
Vitamin K is the main ingredient here, and all ten panelists spoke about it, mostly in its K2 form. Five of them say they take it, usually 90 to 100 mcg of K2 in the morning for general health or longevity, and one of those takes the MK-7 form daily. Four more recommend it, mainly for bone strength and for keeping calcium in the bones and out of arteries and joints. Three of them say to take it with vitamin D, and one also suggests it for kids. Food sources the panel mentioned include leafy greens, natto, butter and liver. The only caution came from one panelist, who warned about too much selenium in some multivitamins, and no one said they stopped.
See all 10 biohackers →Hide the biohackers
Dave Asprey · Vitamin K · recommends
- Explains that Vitamin K2 acts as a traffic cop for calcium, waving it into bones and away from arteries, and that grass-fed butter is one of the only foods with a real amount of K2.
- Recommends taking vitamin K2 with vitamin D to keep calcium in the bones, and suggests kids also take it for stronger bones.
- Recommends Vitamin K2, stating it supports healthy calcium metabolism.
- Recommends adding vitamin K2 to vitamin D supplementation.
- Mentions that natto is a good source of vitamin K2, which is probably its primary benefit.
- Dave Asprey discusses the overlooked link between the microbiome and vitamin K2 production, and its role in bone density.
- Realized that you have to have K2, and that's why vitamin D exists, for the right ratios of all the fat solubles.
- Has done their best to teach people to always take vitamin K2 with vitamin D3, as it is a critical ingredient for avoiding cardiovascular disease and is affordable and powerful.
- Natto also has a substantial dose of vitamin K2, which is hard to get in food.
- Recommends vitamin K2, stating it activates proteins that help move calcium into bones and teeth and reduces calcium deposition in soft tissue like arteries, and suggests getting it from foods like grass-fed dairy and egg yolks or a targeted supplement.
Dr. Eric Berg · Vitamin K · recommends
- Recommends pairing Vitamin D3 with K2, stating that K2 helps keep calcium out of soft tissues.
- Recommends focusing on vitamin K2 to support stronger bones if a neck hump is associated with osteoporosis.
- Discusses foods that contain Vitamin K2.
- States that vitamin K2 is a key nutrient for teeth, as its primary job is to push calcium into bones and teeth, and recommends a supplement dose of 1 to 200 micrograms per day, paired with vitamin D.
- Recommends taking 40 to 45 milligrams of vitamin K2 daily for osteoporosis, citing a study from Japan with great results.
- Mentions that easy bruising can result from a lack of vitamin K1.
- Mentions that grass-fed liver has vitamin K2.
- Recommends getting plenty of vitamin K2 to support joint and metabolic health.
- Recommends vitamin K2 to keep calcium in control and protect against calcium buildup in joints and arteries, which is important for osteoarthritis.
- States that butter is loaded with vitamin K2, which is essential for making teeth strong and keeping calcium out of soft tissues like arteries.
Thomas DeLauer · Vitamin K · recommends
- Recommends taking Vitamin K2 with Vitamin D3 in the morning, along with morning fats, to ensure calcium is directed to the bones and not deposited in arteries or soft tissue.
- Recommends using a multivitamin to ensure adequate micronutrient intake, especially when wholesome food is less available.
- Notes that grass-fed butter provides more Vitamin K2, which plays a role in directing calcium towards bones instead of arteries, contributing to bone health.
- Advises checking multivitamins because many contain 100, 200, or 300% of the daily value of selenium, which can contribute to excessive intake.
- Recommends Vitamin K2 for bone density, stating it must be taken with D3.
- Recommends taking a multivitamin to ensure adequate intake of important cofactors like B vitamins, magnesium, iron, and zinc, which are essential for the signaling system to be operational.
- Recommends a multivitamin stack, specifically Fyhealth, for those who are fasting, as it helps ensure adequate nutrition when calorie and food intake are reduced.
- Warns against synthetic multivitamins, arguing that they are an attempt to be smarter than nature by combining isolated nutrients in proportions not found naturally, and that a whole food approach is superior.
- Vitamin K2 makes sure calcium ends up in your bones instead of your arteries.
- Recommends Thi Health's multi-stage multivitamin, which is broken into AM and PM stacks and uses micro encapsulation beads for delayed absorption, ensuring compounds like magnesium and calcium don't compete.
Dr. Rhonda Patrick · Vitamin K · neutral
- Mentions vitamin K as one of the micronutrients found in multivitamins that people often don't get enough of from their diets.
- Lutein and zeaxanthin can also be obtained from certain multivitamins.
- Mentions that kale delivers vitamin K, a micronutrient many diets fall short on.
- Rhonda takes 100 mcg of Vitamin K2 (MK-7) daily for general health.
- Choosing a multivitamin that includes lutein and zeaxanthin ensures you get meaningful amounts every day.
- Rhonda includes Vitamin K2 in her supplement routine.
- Takes Vitamin K2 at night.
- Notes additional gaps in vitamin K.
- Suggests avoiding a multivitamin if it contains biotin before a testosterone blood test to prevent confounding results.
- Multiple randomized controlled trials show older adults taking a standard multivitamin (like Centrum Silver) had measurable improvements in processing speed, cognition, and episodic memory.
Bryan Johnson · Vitamin K · uses
- Takes 90 mcg of Vitamin K2 in the morning for general health.
- Takes 100 mcg of Vitamin K2 in the morning for longevity.
- He takes 100 mcg of Vitamin K2 in the morning for general health.
- Takes 100 mcg of Vitamin K2 in the morning for longevity.
- Takes 90 mcg of Vitamin K2 in the morning.
- Takes 100 mcg of Vitamin K2 in the morning.
- Takes 100 mcg of Vitamin K2 in the morning.
- Takes 90 mcg of Vitamin K2 in the morning for longevity.
- Takes 100 mcg of Vitamin K2 in the morning.
- He takes 100 mcg of Vitamin K2 in the morning.
Ben Greenfield · Vitamin K · neutral
- Discusses vitamin K2, specifically the menaquinone forms, as crucial for arterial health and notes that it breaks down into MK-4 and MK-7.
- Explains that gut bacteria liberate K from the diet or make the K needed, and that poor absorption of vitamin K due to bacterial imbalances is linked to heart disease.
- Recommends taking vitamin K complex as a co-factor to increase vitamin D absorption.
- Lists vitamin D3 and K2 for the immune system as a recommended intervention on the True Age test.
- Recommends adequate intake of vitamin K for bone strength.
- Takes 90 mcg of Vitamin K2 in the morning.
- Takes 100 mcg of Vitamin K2 in the morning for longevity.
- He takes 100 mcg of Vitamin K2 in the morning for general health.
- Takes 100 mcg of Vitamin K2 in the morning for longevity.
- Takes 90 mcg of Vitamin K2 in the morning.
Siim Land · Vitamin K · neutral
- Notes that Vitamin K2 helps activate proteins involved in bone mineralization and calcium regulation.
- Mentions that prunes contain vitamin K, which is a factor in their ability to help with bone density.
- Recommends Vitamin K2 for bone health and calcium metabolism, based primarily on human research, especially randomized controlled trials showing measurable benefits.
- Lists Vitamin K2 as one of 15 supplements backed by human studies.
- Lists leafy greens as a source of Vitamin K1.
- Thinks vitamin K2 has some of the strongest evidence and is worth considering.
- Notes that Vitamin K2 pairs well with vitamin D by regulating calcium and bone mineralization.
- Recommends pairing magnesium with vitamin K2, as it ensures that calcium mobilized by active vitamin D ends up in bones and teeth rather than arterial walls.
- He takes 100 mcg of Vitamin K2 in the morning for general health.
- Takes 90 mcg of Vitamin K2 in the morning for general health.
Andrew Huberman · Vitamin K · uses
- Takes 90 mcg of Vitamin K2 in the morning for longevity.
- Takes 90 mcg of Vitamin K2 in the morning.
- He takes 90 mcg of Vitamin K2 in the morning for overall health.
- Takes 100 mcg of Vitamin K2 in the morning.
- Takes 90 mcg of Vitamin K2 in the morning for general health.
- Takes 100 mcg of Vitamin K2 every day for longevity.
- He takes 90 mcg of Vitamin K2 every morning.
- He takes 100 mcg of Vitamin K2 in the morning for general health.
- He takes 100 mcg of Vitamin K2 in the morning.
- Notes that many people are deficient in fat-soluble vitamins, particularly vitamin K2.
Dr. Mark Hyman · Vitamin K · uses
- Takes 100 mcg of Vitamin K2 in the morning for general health.
- Takes 100 mcg of Vitamin K2 in the morning.
- Takes 90 mcg of Vitamin K2 in the morning for overall health.
- States that green leafy vegetables are great sources of vitamin K.
- Lists Vitamin K as important for bone health.
- Takes 90 mcg of Vitamin K2 in the morning.
- Takes 100 mcg of Vitamin K2 in the morning.
- Takes 90 mcg of Vitamin K2 in the morning for general health.
- Mentions Vitamin K as one of the things given to newborn babies in the first couple of days, alongside Hepatitis B and RSV vaccines, without taking a specific stance on its use.
- Explains that vitamin K1 is very important for blood coagulation, as the body triages it to essential functions to prevent acute death.
Peter Attia · Vitamin K · uses
- Takes 100 mcg of Vitamin K2 in the morning to maintain levels.
RAL Summary
Members OnlyTier 4 for Bone Health
The tier-2 grade rests mainly on trials of vitamin K2 (menaquinone) and of vitamin K combined with vitamin D, but this product is vitamin K1 (phytonadione), and the two trials that tested vitamin K1 alone found no change in bone density. So it is graded Tier 4, lower than the rules alone gave.
Take 2 servings a day (2 tablets) to match the dose that worked in the studies.
- Emerging: not enough evidence to rank higher yet.
Where the evidence disagrees: 16 of the 50 human studies found no effect.
More Details
Members OnlyBody systems · Combine with · Possible side effects
Body systems: Skeletal system, Blood and clotting
Combine with: To maximize the benefits of Vitamin K for bone health, consider combining it with Vitamin D, as Vitamin D is crucial for calcium absorption, and Vitamin K2 helps direct this calcium to the bones and away from soft tissues. Calcium itself is a fundamental building block for bones, so a good dietary intake or supplementation is often recommended. Magnesium also plays a vital role in bone mineral density and helps activate Vitamin D.
Possible side effects: The vitamin K2 review found no extra side effects compared with placebo. Some buyers disliked how tiny the tablets are.
Supplement Facts
Vitamin K 100 mcg
| Vitamin K (as Phytonadione) | 100 mcg | 83% |
Other ingredients: Dicalcium Phosphate, Vegetable Cellulose, Vegetable Stearic Acid, Vegetable Magnesium Stearate.
Directions: For adults, take one (1) tablet daily, preferably with a meal.
Label source: Puritan · Report a label change
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Graded October 28, 2026 by the Reverse Age Lab evidence engine, from human studies, real reviews and our biohacker panel. How we grade. Is this medical advice? No. Rala organizes the published evidence; go over any change with your doctor, especially if you take meds.
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