NOW Vitamin K-2 100 mcg
Brand: NOW · Form: CAPSULE [E0159]
Our assessment
The evidence shows that NOW Vitamin K-2 100 mcg is a specific form of vitamin K that works in tandem with other nutrients for bone and cardiovascular health. However, data directly on this product is limited, and the primary data available involves the mineral calcium, which is often taken alongside vitamin K-2. Our assessment is that while vitamin K-2 is generally considered safe, you should be aware of potential interactions if you are also taking calcium supplements.
How it works
Vitamin K-2 acts as a key activator for proteins that help direct calcium to your bones and teeth, rather than allowing it to build up in your arteries. This process is critical for bone mineralization and supports neuromuscular relaxation [NIH ODS]. Think of it as a traffic director for calcium in your body, ensuring it goes where it's needed most.
Safety profile
The total adverse event reports for the broader product category are 592,059 [FDA data]. For the specific ingredient calcium (which is often taken with vitamin K-2), high intakes are linked to risks including constipation, nausea, abnormal heart rhythms, and a high risk of death from heart disease [NIH ODS]. Data on side effects specific to NOW Vitamin K-2 100 mcg alone is not available. You should be aware that calcium supplements can reduce the absorption of medications such as bisphosphonates, tetracycline antibiotics, and levothyroxine [NIH ODS].
Our recommendation
Our recommendation is to use this product as part of a targeted strategy for bone health, but only if you do not have a history of blood clotting disorders. Since vitamin K-2 can interact with blood thinners like warfarin, consult your doctor before starting. If you also take calcium, do not exceed 500 mg of calcium at one time to improve absorption, and be mindful of the safety risks associated with high calcium intakes [NIH ODS].
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | NOW |
|---|---|
| Serving Size | |
| Contents | 100.0 Veg Capsule(s) |
| Market Status | Off Market |
How to Read This Label
Supplement labels contain several key sections regulated by the FDA:
- Serving Size — The recommended amount per dose. Always check this — some products require multiple capsules per serving.
- Amount Per Serving — Shows the quantity of each nutrient in the product, typically in IU (International Units), mg (milligrams), or mcg (micrograms).
- % Daily Value (%DV) — Indicates how much a nutrient in a serving contributes to a daily diet. 5% DV or less is low; 20% DV or more is high.
- Other Ingredients — Lists inactive ingredients like fillers, binders, and capsule materials (e.g., gelatin, cellulose, magnesium stearate).
- Suggested Use — The manufacturer's recommended directions for taking the supplement, including timing and dosage.
Source: FDA Dietary Supplement Labeling Guide