If you’re into health and wellness, you’ve probably heard of vitamins like C and D, but what about vitamin K2? It’s like the quiet kid in class who’s secretly a genius.
This lesser-known nutrient is starting to get some serious attention, and for good reason. From stronger bones to a healthier heart, vitamin K2 is a powerhouse that deserves a spot in your wellness routine.
As a copywriter who loves diving into the science behind health trends, I’ve scoured the latest research, expert opinions, and user reviews to bring you this 2025 guide.
Let’s unpack the seven science-backed benefits of vitamin K2, how it works, and what real people are saying about it. Ready? Let’s dive in!
What Is Vitamin K2, Anyway?
Vitamin K is a fat-soluble vitamin that comes in two main forms: K1 (phylloquinone) and K2 (menaquinone). K1 is found in leafy greens like spinach and kale and is best known for helping blood clot. K2, on the other hand, is found in animal products (like egg yolks and butter), fermented foods (like natto and sauerkraut), and some cheeses. Your gut bacteria also produce small amounts of K2, but not enough to meet your needs.
K2 has several subtypes, with MK-4 and MK-7 being the most studied. MK-4 comes from animal sources, while MK-7, which lasts longer in your body, comes from fermented foods like natto.
What makes K2 special is its role in directing calcium where it belongs—into your bones and teeth—and keeping it out of places it shouldn’t be, like your arteries. Think of it as a traffic cop for calcium. Now, let’s get to the good stuff: the seven science-backed benefits of vitamin K2.
7 Science-Backed Benefits of Vitamin K2
1. Strengthens Bones and Fights Osteoporosis
If you’re worried about brittle bones as you age, K2 is your ally. It activates a protein called osteocalcin, which binds calcium to your bones, making them stronger and denser. A 2022 meta-analysis of 16 studies involving 6,425 postmenopausal women found that K2 supplements improved bone mineralization and strength.
Another study from 2019 showed that 5 mg of MK-4 daily reduced undercarboxylated osteocalcin (a marker of weak bones) in postmenopausal women with fractures, bringing levels closer to those of healthy premenopausal women.
K2’s bone benefits don’t stop at density—it also reduces fracture risk. A 2015 meta-analysis found that high-dose K2 (45 mg/day) cut hip fractures by 77%, vertebral fractures by 60%, and non-vertebral fractures by 81%. Even lower doses (100–360 mcg) show promise, especially when paired with vitamin D and calcium.
What users say: WebMD reviewers report stable or improved DEXA scans after taking K2 (MK-7) with calcium and magnesium. One user said, “My doctor was amazed—my bone density barely changed in two years!”
2. Protects Your Heart
Heart disease is a leading cause of death, and K2 might help keep your ticker in check. It activates matrix Gla protein (MGP), which prevents calcium from building up in your arteries—a process called arterial calcification that can lead to heart attacks and strokes. A 2020 study found that higher K2 intake was linked to a lower risk of coronary heart disease. Another study showed that for every 10 mcg of K2 consumed daily, the risk of heart disease dropped by 9%.
A 2015 review noted that K2-rich diets (like those including natto) are associated with less arterial stiffness and lower cardiovascular mortality. A 2021 clinical trial of 244 postmenopausal women taking 180 mcg of MK-7 daily for three years showed improved vascular elasticity and less arterial stiffening compared to a placebo group.
What users say: A WebMD user reported that after starting K2 (MK-7) with vitamin D3, their ophthalmologist noticed no arterial plaques in their optic arterioles a year later. X posts from 2025 call K2 a “heart disease preventer” for its plaque-reducing effects.
3. Boosts Dental Health
Your teeth are like mini-bones, so it makes sense that K2 helps them too. By activating osteocalcin, K2 supports dentin (the calcified tissue under enamel), strengthening teeth. A 2023 review of 4,965 elderly people found that K2 supplementation, paired with moderate fiber intake, helped prevent tooth loss from periodontal disease, especially in men. K2 also reduces plaque buildup by directing calcium to teeth instead of soft tissues.
What users say: X posts rave about K2’s dental benefits, with users like @dr_ericberg claiming it “remineralizes teeth” and reduces cavities when combined with vitamin D3. WebMD users report less tartar and stronger teeth after adding K2 to their routines.
4. Reduces Inflammation
Chronic inflammation is behind many health issues, from arthritis to heart disease. K2 may help by lowering inflammatory markers like C-reactive protein (CRP). A 2020 review found that K2 supplementation reduced inflammation in rheumatoid arthritis patients by decreasing CRP levels. This anti-inflammatory effect might also explain K2’s potential to ease joint pain and improve conditions like osteoarthritis.
What users say: X users like @Outdoctrination praise K2 for “reducing gut inflammation” and improving overall health. A WebMD reviewer taking K2 with D3 noted less joint stiffness and better mobility after a month.
5. Supports Mental Health
K2’s benefits aren’t just physical—it might lift your mood too. A small 2022 study in women with polycystic ovary syndrome (PCOS) found that eight weeks of MK-7 supplementation significantly reduced depression symptoms. Animal studies suggest K2 improves anxiety and depression by stabilizing blood sugar and reducing inflammation in the brain. X posts even claim K2 acts as an “anti-depressant” and “anti-anxiety” nutrient, though human studies are limited.
What users say: WebMD users report better sleep and mood after taking K2 (90 mcg) with D3 before bed. One said, “I’m sleeping eight hours and waking up refreshed!” X users call K2 a “silver bullet” for mental health, though these claims need more research.
6. May Protect Your Brain
Emerging research suggests K2 could support brain health as you age. Six studies in people over 65 linked low K2 intake to worse cognitive performance and behavior. K2 may protect brain cells from amyloid-beta toxicity (linked to Alzheimer’s disease) and reduce neuroinflammation. A 2023 review concluded that K2 has potential to slow Alzheimer’s progression, though more clinical trials are needed. K2’s role in reducing arterial stiffness might also lower dementia risk, as stiff arteries are tied to cognitive decline.
What users say: X posts claim K2 “reverses aging in the brain,” but these are anecdotal. WebMD users report feeling sharper after combining K2 with other nutrients, though specific brain benefits are hard to pinpoint.
7. Enhances Exercise Performance
Here’s a bonus for fitness buffs: K2 might give your workouts a boost. A 2017 study found that eight weeks of K2 supplementation (as MK-7) increased maximal cardiac output during exercise, suggesting better heart and muscle efficiency. This could be due to K2’s role in mitochondrial metabolism, similar to Coenzyme Q10, which supports energy production.
What users say: X users like @Outdoctrination call K2 a “mitochondrial powerhouse” for its energy-boosting effects. Athletes on WebMD report feeling less fatigued during workouts after adding K2 to their stacks.
How to Get Vitamin K2: Food vs. Supplements
You can get K2 from foods, but it’s trickier than K1. Here are the best sources:
- Natto: A Japanese fermented soybean dish with 850–1,000 mcg of MK-7 per 100 grams. It’s the K2 king but not everyone loves its slimy texture.
- Cheeses: Gouda and Brie offer 20–50 mcg per ounce.
- Egg yolks: 67–192 mcg per yolk, depending on the hen’s diet.
- Butter: 2.1 mcg per tablespoon from grass-fed cows.
- Sauerkraut: 2.75 mcg per half-cup.
- Organ meats: Liver and chicken provide small amounts.
Most Western diets are low in K2 because we don’t eat much natto or organ meats. The average intake is about 15–45 mcg/day, while studies suggest 100–360 mcg for optimal benefits. Your body can convert some K1 to K2, but the process is inefficient, so direct K2 sources or supplements are often needed.
Supplements: K2 supplements come as MK-4 (higher doses, like 1–5 mg) or MK-7 (lower doses, 50–360 mcg). MK-7 is more bioavailable and lasts longer in your body. Popular brands include:
- Sports Research Vegan D3 + K2: Top-rated on Amazon with 89,000 five-star reviews for its MenaQ7 MK-7 and vegan D3.
- Now Foods MK-7 Plus K1 and MK-4: Praised for its broad-spectrum formula.
- Life Extension Super K: Combines K1, MK-4, and MK-7 for comprehensive support.
- Healthy Origins MK-7: Budget-friendly and high-potency.
Dosage: Aim for 90–120 mcg/day for general health, 180–360 mcg for heart benefits, or up to 5 mg for osteoporosis (under medical supervision). Take K2 with a fatty meal for better absorption.
Safety: K2 is safe up to 45 mg/day, with no reported toxicity. But if you’re on blood thinners like warfarin, talk to your doctor—K2 can interfere with their effects.
What Users Are Saying in 2025
The K2 hype is real, especially on X and review sites:
- Bone health: Postmenopausal women report stable DEXA scans and less joint pain with K2, D3, and calcium. A WebMD user said, “My muscles feel supple again after K2 fixed my calcium issues.”
- Heart health: Users combining K2 with D3 notice lower blood pressure and fewer arterial plaques. One reported a drop from 125/76 to 100/66.
- Dental wins: X users claim K2 reduces plaque and strengthens teeth, with @dr_ericberg calling it a “dental health game-changer.”
- Mood and energy: Users report better sleep, less anxiety, and more stamina. An X post called K2 an “anti-depressant” and “mitochondrial booster.”
- Side effects: Some experience mild stomach upset initially, but it’s rare. Users on blood thinners warn about checking with doctors.
On the flip side, some users don’t notice changes, especially at low doses (80–100 mcg). Higher doses (500 mcg–5 mg) get better feedback but aren’t for everyone.
The Science: What’s Solid and What’s Shaky?
K2’s benefits for bones and heart health are backed by strong evidence. Meta-analyses and clinical trials confirm it reduces fracture risk and arterial calcification, especially in postmenopausal women. Dental health benefits are supported by smaller studies, and inflammation reduction shows promise in arthritis and diabetes.
Mental health and cognitive benefits are less certain. The PCOS depression study is intriguing but small, and Alzheimer’s research relies on animal studies and reviews. Exercise performance data is limited to one study, so more research is needed. Claims on X about K2 “reversing aging” or doubling testosterone (based on rat studies) are overstated and lack human evidence.
A 2024 ConsumerLab review notes that many “bone health” supplements skimp on K2 or fail quality tests, so choose reputable brands like Sports Research or Now Foods. The FDA hasn’t approved health claims for K2, unlike Europe and Asia, due to gaps in long-term data.
Final Thoughts: Should You Try Vitamin K2 in 2025?
Vitamin K2 is like a Swiss Army knife for your health. Its ability to strengthen bones, protect your heart, boost dental health, and reduce inflammation is backed by solid science, with emerging perks for mood, brain health, and exercise performance. While it’s not a miracle cure, it’s a low-risk, high-reward addition to your routine, especially if you’re over 50, postmenopausal, or low on K2-rich foods like natto.
Start with a diet rich in K2 (think cheese, egg yolks, or sauerkraut), but if that’s not enough, a supplement like Sports Research D3 + K2 or Life Extension Super K is a smart bet. Stick to 100–360 mcg of MK-7 for general health, and pair it with vitamin D3 for maximum impact. If you’re on blood thinners or have health conditions, check with your doctor first.
In 2025, K2 is gaining fans for its versatile benefits and clean safety profile. Whether you’re aiming for stronger bones or a healthier heart, this nutrient is worth a look. Have you tried K2, or are you curious to start? Drop your thoughts in the comments, and let’s keep the conversation going! Here’s to vibrant health this year!