Vitamin K-2 100 mcg
NOW
Vitamin K-2 100 mcg
4.8
★ ★ ★ ★ ★
(13824 ratings)
Vitamin K 100 mcg
Score 62.0
A very affordable Vitamin K2 (MK-4) supplement, but the low dosage of MK-4 and absence of Vitamin D3 limits its effectiveness for optimal bone and heart health compared to more potent alternatives.
Quantity: 100 Capsule(s)Servings size: 1 Veg Capsule(s) (100 servings)
Selected goals:
Other goals:
Bone Health
Heart Health
Cardiovascular Support
General Health
leaderboard Score 62.0
A very affordable Vitamin K2 (MK-4) supplement, but the low dosage of MK-4 and absence of Vitamin D3 limits its effectiveness for optimal bone and heart health compared to more potent alternatives.
insights Analysis
NOW Vitamin K-2 100 mcg provides Menaquinone-4 (MK-4) at a very accessible price point, making it popular as evidenced by its high review count. While MK-4 is a form of Vitamin K2, nutritionists and research suggest that for systemic effects on bone and arterial health, higher doses (often in milligrams) are typically needed, or the MK-7 form is preferred due to its longer half-life. At 100 mcg, this MK-4 dose offers minimal benefit for targeted goals. The addition of Alfalfa powder is largely irrelevant for the primary K2 benefits. Crucially, the absence of Vitamin D3 means it misses out on the essential synergy that optimizes K2's role in calcium metabolism for bones and arteries.
- Extremely cost-effective with a very low price per serving.
- High review count suggests wide acceptance and popularity.
- Contains Vitamin K2 as MK-4, which at this low 100 mcg dose is less effective for systemic benefits than MK-7.
- Lacks Vitamin D3, a critical synergistic nutrient for K2's bone and cardiovascular benefits.
- Alfalfa powder inclusion does not significantly contribute to the targeted Vitamin K benefits.
$9.59($0.09 per serving)
 Vitacost | $ 9.59 | |
 Daily Vita | $ 9.90 | |
 Pure Formulas | $ 10.11 | |
 iHerb | $ 10.40 | |
 Walmart | $ 12.20 |
bolt Effectiveness for goals
Vitamin K is essential for proper blood clotting and plays a significant role in bone metabolism. It helps the body produce proteins necessary for these vital bodily functions.
Vitamin K activates proteins such as osteocalcin, which are crucial for incorporating calcium into the bone matrix. This mechanism supports bone mineralization and helps maintain bone density.
Vitamin K1 (phylloquinone) is primarily effective for blood coagulation and is abundant in green leafy vegetables. Vitamin K2 (menaquinones) is more involved in bone and cardiovascular health, found in fermented foods and animal products, and has different bioavailabilities.
Emerging research suggests that Vitamin K, particularly K2, may help prevent arterial calcification by activating matrix Gla protein. This protein helps inhibit calcium deposition in soft tissues, supporting arterial flexibility.
Vitamin K works synergistically with calcium by helping to direct calcium to the bones and away from soft tissues like arteries. It activates proteins like osteocalcin for bone binding and matrix Gla protein to inhibit soft tissue calcification.
schedule Dosage, timing & forms
Recommended dosages for Vitamin K vary by age and form (K1 vs K2). For adults, the Adequate Intake (AI) for Vitamin K is 120 mcg per day for men and 90 mcg per day for women. Specific supplemental dosages may differ depending on individual needs and health goals.
Yes, dosages can differ between Vitamin K1 and K2 due to their varying potencies and half-lives. While K1 is measured in micrograms (mcg) for general intake, K2 (especially MK-7) may be effective at lower microgram doses due to its longer half-life. It's important to check the specific form and dosage on the supplement label.
Yes, Vitamin K is a fat-soluble vitamin, meaning it is best absorbed when taken with a meal containing some dietary fat. This helps facilitate its absorption into the body.
The two main forms of Vitamin K found in supplements are Vitamin K1 (phylloquinone) and Vitamin K2 (menaquinone). Vitamin K2 further has various subtypes, with MK-4 and MK-7 being the most common in supplements. Each form may have distinct roles and bioavailability.
There is no established Upper Limit (UL) for Vitamin K from food or supplements, as toxicity is rare. However, high doses of synthetic Vitamin K (menadione, K3) can be toxic, though this form is not typically found in supplements. Always adhere to recommended dosages and consult a healthcare provider if you have concerns.
health_and_safety Safety & interactions
Vitamin K plays a crucial role in blood clotting, which is the opposite effect of anticoagulant medications such as warfarin. Consuming inconsistent amounts of Vitamin K can alter warfarin's effectiveness, potentially making the blood thinner less effective or increasing bleeding risk. Individuals taking warfarin should maintain a consistent intake of Vitamin K and consult their healthcare provider.
Individuals taking anticoagulant medications like warfarin should consult their doctor before taking Vitamin K supplements due to potential interactions. People with certain liver conditions or those with a G6PD deficiency should also seek medical advice before supplementation. Always discuss new supplements with a healthcare provider.
Vitamin K supplements are generally considered safe for most healthy individuals when taken at recommended dosages. Side effects are uncommon but can include upset stomach, diarrhea, or allergic reactions in sensitive individuals. High doses of synthetic Vitamin K (menadione, K3) can be toxic, but this form is rarely used in supplements.
Vitamin K is essential during pregnancy and breastfeeding, and adequate intake is important for both mother and child. However, supplementation during these periods should only be undertaken under the guidance of a healthcare professional. High doses are generally not recommended without specific medical advice.
There is currently no established Tolerable Upper Intake Level (UL) for Vitamin K from food or supplements due to its low potential for toxicity. However, excessive intake, especially of synthetic forms, could potentially have adverse effects. It is always best to adhere to recommended dosages on supplement labels or as advised by a healthcare professional.
Ingredients
| Ingredient | Amount per serving |
|---|---|
Vitamin K2 | 100 mcg |
Alfalfa powder | 250 mg |
Categories
Vitamin K 70.0
It's a straightforward Vitamin K2 (MK-4) product that is highly affordable, making it a good entry-level option for those seeking this specific form of K2.
Goals
Bone Health 60.0
While MK-4 has a role in bone metabolism, this 100 mcg dose is too low for significant therapeutic effects, and the absence of Vitamin D further limits its impact on bone density.
Heart Health 60.0
The low dose of MK-4 means its contribution to arterial health and calcification prevention is likely minimal compared to higher doses or MK-7, especially without D3.
Its support for cardiovascular health is limited by the suboptimal dosage and form of K2 for this purpose, and the lack of crucial co-factors like Vitamin D.
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