Vitamin K often flies under the radar, but it’s key for blood clotting and strong bones. If you’ve ever wondered how much you should take—whether from food or a pill—this guide breaks it down in plain English. No jargon, just clear numbers and easy steps so you can feel confident about your vitamin K intake.
There are two main forms: K1 (phylloquinone) found in leafy greens, and K2 (menaquinone) that shows up in fermented foods and some animal products. Both help your liver produce clotting factors, but K2 also supports calcium management in bones and arteries. Most people get enough K1 from a regular diet, but K2 can be trickier, especially if you don’t eat a lot of cheese, natto, or egg yolks.
The recommended daily allowance (RDA) is simple: 90 µg for adult women and 120 µg for adult men. That’s roughly a cup of cooked kale or a handful of spinach. If you’re taking a supplement, most over‑the‑counter products offer 45‑100 µg per tablet, which aligns with the RDA.
When you’re on blood‑thinners like warfarin, you’ll need a steadier intake. In that case, aim for the same daily amount from food and keep supplement doses low (often 25‑50 µg) unless your doctor says otherwise. Sudden jumps in vitamin K can mess with your medication’s effectiveness.
If you’re pregnant, nursing, or have a condition that affects fat absorption, you might need extra K2. A typical supplement dose for those groups is 90‑180 µg per day, but always check with a healthcare professional first.
Here’s a quick way to gauge your intake: add up the µg on nutrition labels for the foods you eat in a day. If you hit the RDA, you probably don’t need a supplement. If you fall short, a low‑dose K2 pill can fill the gap without overdoing it.
Remember, vitamin K isn’t a “more is better” nutrient. Excessive doses (over 1 mg per day) can cause unwanted clotting and interact with medications. Stick to the RDA, adjust only under medical advice, and you’ll keep your blood and bones happy.
A practical guide to vitamin K: what it does, K1 vs K2, how much you need, the best foods, supplement tips, and safety for meds like warfarin.