Cauliflower: Nutrients, What Research Shows and Safety

Cauliflower (Brassica oleracea var. botrytis) is a vegetable in the cabbage family (Brassicaceae). The part we eat is the dense flower head, called the curd, which is usually white but can also be green, yellow or purple. People eat it for its vitamins and fiber, as a low-calorie side dish and as a stand-in for rice or flour. This page keeps the food apart from supplements and from hype, and says what research does and does not show. It is information, not a plan for what to eat.

Read this first

• If you take warfarin (a blood thinner), MedlinePlus lists cauliflower among foods high in vitamin K and says sudden changes in vitamin K intake can change how the medicine works. The advice is to eat about the same amount every day and ask your provider. [2]
• Gas and bloating: the NHS lists cauliflower among hard-to-digest foods that can cause wind and bloating in some people. [4] Allergic reactions to any food are possible. For trouble breathing or swelling of the face or throat, call 911.
• Thyroid: reviews of the research found no harm to thyroid function from eating brassica vegetables, especially when iodine intake is adequate. Ask your clinician if you have a thyroid condition. [6][7]
• Evidence in one line: cauliflower is a good source of vitamin C and a useful source of vitamin K, folate and choline. Studies of people who eat more vegetables overall show better health, but we found no good evidence that cauliflower itself prevents or treats a disease.

What is in it (USDA values)

Source: USDA FoodData Central, "Cauliflower, raw" (SR Legacy, FDC 169986). [1] % Daily Value uses the FDA 2016 Daily Values; values vary with variety, ripeness and storage. Per-serving numbers are our arithmetic from the USDA per-100 g values.

Cauliflower contains glucosinolates, sulfur-containing compounds found in cruciferous vegetables. A Linus Pauling Institute review lists 22 mg of total glucosinolates in half a cup (50 g) of chopped raw cauliflower, and notes that cauliflower gave the lowest isothiocyanate yield (1.5 micromoles per 100 g) among nine vegetables tested. [9] When glucosinolates break down they form isothiocyanates such as sulforaphane. Most of the protective findings for these compounds come from cell and animal studies; the same review calls clinical evidence of protection in people "scarce." [9] Colored varieties differ: one 2026 comparison found green curds had more sulforaphane and yellow or gold curds more flavonoids and phenolic acids. [16] USDA lists no carotenoids in white cauliflower, apart from a trace of lutein plus zeaxanthin (1 mcg per 100 g). [1]

What research says

Eaten as food vs taken as a supplement or extract. Everything in the table is about the whole vegetable except the glucosinolate rows, where laboratory work often uses purified sulforaphane or broccoli extracts. Those results do not carry over to cauliflower on a plate, and cauliflower supplements are a different product that we do not cover. Eating cauliflower is not a substitute for medicine.

How much is a normal serving

• USDA household portion: 1 cup chopped raw (107 g); one floweret is 13 g. [1]
• NHS: 80 g of fresh, canned or frozen vegetables counts as one of the "5 A DAY" portions (last reviewed 9 June 2026). [15] A cup of chopped cauliflower is a little more than one portion by that measure.
• WHO: at least 400 g of fruits and vegetables a day for people over 10 (fact sheet dated 26 January 2026). [14]
• These are public-health figures for information, not a prescription.
• Cooking: a 2026 study found cauliflower had the lowest sulforaphane of four brassicas tested, that cooking and freezing lowered it, that pan-frying lost the most, and that boiling moved much of it into the cooking water. [10] Cooking inactivates the plant enzyme (myrosinase) that makes isothiocyanates, though light steaming under about five minutes keeps some; gut bacteria can still produce some after cooking. [9] We did not find a source on vitamin C loss in cauliflower, so no claim is made. See fresh, frozen and canned produce.

Safety, allergy and medicines

• Warfarin and vitamin K: MedlinePlus names cauliflower among high-vitamin-K foods and says to keep intake steady rather than swing up or down; ask your provider whether to monitor it. [2] One cup raw gives about 14% of the Daily Value for vitamin K. [1]
• Gas, bloating and IBS: the NHS suggests avoiding cabbage-family foods such as cauliflower if you have wind, bloating or cramps. [4] See the NHS list of when to see a doctor: bloating that is frequent, lasts after changing diet, or comes with weight loss, blood in stool, vomiting or fever needs medical advice. [3] We did not find a source we could read that gives the FODMAP content of cauliflower, so we do not state one. Anyone trying a low-FODMAP diet should do it with a dietitian.
• Thyroid and goitrogens: cruciferous vegetables contain goitrin and thiocyanate precursors that, in lab settings, can interfere with thyroid iodine uptake. One review of goitrin content found it minimal in common commercial brassicas and concluded thiocyanate from them is low risk. [7] The 2024 systematic review concluded daily brassica intake, especially with adequate iodine, poses no adverse effects on thyroid function. [6] This is reassurance for normal food amounts, not advice for people with thyroid disease or those taking thyroid medicine; ask your clinician. See thyroid conditions and iodine.
• Kidney disease and potassium: cauliflower has 299 mg potassium per 100 g (6% Daily Value). [1] We did not read a source that sets limits for cauliflower in kidney disease, so we make no claim; people on potassium restriction should follow their care team's plan.
• Allergy: we did not find a source we could read on cauliflower allergy. Food allergy can happen with any food; see food allergy basics and emergency signs.
• Pregnancy: the Linus Pauling Institute says the need for choline is probably higher in pregnancy and fewer than 9% of pregnant women in US survey data meet the adequate intake. [11] That is information about choline in the diet. We found no source that singles out cauliflower for or against in pregnancy.
• Pesticide residues and iodine fortification: we did not read a source on cauliflower residues, so we make no claim. A 2026 laboratory study explored cauliflower as a carrier for iodine fortification (it tracked iodine stability and goitrogenic compounds after steaming or boiling); this is food-technology work, not a health trial. [12]

Choosing, storing and food safety

• Avoid bruised or damaged produce. Keep cut or pre-cut cauliflower in the refrigerator at 40°F (4°C) or below. [13]
• Rinse under running water. The FDA says soap, detergent or commercial produce wash is not recommended, and that washing reduces bacteria but does not remove them all. [13]
• Use separate cutting boards for produce and raw meat, poultry and seafood. [13]
• Frozen and canned vegetables count as portions too; see fresh, frozen and canned produce.

Related pages

• Cruciferous vegetables
• Sulforaphane and glucosinolates in cruciferous vegetables
• Foods and medicine interactions: vitamin K, grapefruit and others
• Foods for gut health and bloating
• Fresh, frozen and canned produce
• Thyroid conditions and iodine