Cauliflower is low in vitamin K. A half-cup serving contains just 9 to 10 micrograms, which is a small fraction of the 90 to 120 mcg adults need daily. If you’re watching your vitamin K intake because of a blood-thinning medication, cauliflower is one of the safer cruciferous vegetables to eat regularly.
How Much Vitamin K Is in Cauliflower
A half-cup of raw or cooked cauliflower provides about 9 to 10 mcg of vitamin K. A full cup of cooked cauliflower comes in at roughly 8.5 mcg (slightly less per cup due to how the florets compact when cooked). The U.S. Department of Veterans Affairs classifies cauliflower as a “low vitamin K food,” defined as containing between 5 and 25 mcg per serving.
For context, the adequate daily intake of vitamin K is 120 mcg for adult men and 90 mcg for adult women, according to the National Institutes of Health. A half-cup of cauliflower covers less than 10% of that recommendation. You’d need to eat a very large amount of cauliflower in a single sitting to get a meaningful dose of vitamin K from it alone.
Cauliflower vs. Other Cruciferous Vegetables
Cauliflower stands out among its botanical relatives for how little vitamin K it contains. Most other cruciferous vegetables land in the moderate or high categories. Here’s how a half-cup cooked serving compares:
- Cauliflower: 9–10 mcg (low)
- Cabbage: 62 mcg (moderate)
- Broccoli: 110 mcg (high)
- Brussels sprouts: 109 mcg (high)
- Kale: 247 mcg (high)
- Collard greens: 305–530 mcg (high)
- Turnip greens: 265–425 mcg (high)
- Mustard greens: 415 mcg (high)
Broccoli, cauliflower’s closest cousin in the kitchen, has roughly 11 times more vitamin K per serving. Kale has about 25 times more. If you’re looking for a cruciferous vegetable that won’t significantly shift your vitamin K intake, cauliflower is the clear choice.
What This Means for Blood Thinners
People taking warfarin (sometimes sold as Coumadin) are often told to watch their vitamin K intake because the vitamin plays a direct role in blood clotting, and it can reduce the drug’s effectiveness. This leads many people to wonder whether they need to avoid entire food groups, including cruciferous vegetables.
The key guidance from clinical nutrition resources is not to avoid vitamin K foods entirely but to keep your intake consistent from day to day. Warfarin dosing is calibrated to your usual diet. Large swings in vitamin K, like eating no greens for a week and then having a big kale salad, can throw off how well the medication works. Eating roughly the same amounts on a regular schedule matters more than the total number.
Because cauliflower is so low in vitamin K, it’s unlikely to cause a meaningful fluctuation even if you eat it several times a week. A British Columbia government guide for warfarin patients lists cauliflower as a “medium” vitamin K food per 100-gram serving, but explicitly notes that the list is “NOT a list of foods to avoid.” The practical takeaway: cauliflower is one of the easiest vegetables to fit into a warfarin-compatible diet without much worry about day-to-day variation.
Other Nutrients in Cauliflower
While cauliflower won’t contribute much to your vitamin K needs, it offers other nutritional value. A cup of cooked cauliflower is a solid source of vitamin C, providing roughly half of the daily recommended amount. It also supplies fiber, B vitamins (particularly folate and B6), and small amounts of potassium and manganese, all for about 30 calories per cup. Its low vitamin K content simply means you’ll need other foods, particularly leafy greens, to meet that specific nutrient requirement.