Swiss Chard: Nutrients, What Research Shows and Safety

Swiss chard (Beta vulgaris subsp. vulgaris, the same species group as beets, in the amaranth family) is a leafy vegetable. The large green leaves and the colorful stalks are both eaten, raw or cooked. People eat it for its vitamins, minerals and plant pigments. This page looks at the food itself and keeps it apart from supplements and from hype. It is information only, not a plan for what to eat.

Read this first

• Vitamin K and warfarin: chard is very high in vitamin K. People who take warfarin are told to keep vitamin K foods steady from day to day, because sudden changes can change how the medicine works. Ask the prescriber or pharmacist. [2]
• Oxalate and kidney stones: people who have had calcium oxalate stones are told by NIDDK that some leafy foods, such as spinach, may be worth limiting. [3] A 2026 case report describes sudden kidney injury after one large meal of freshly harvested chard. [4]
• Potassium and kidney disease: leafy greens are a potassium source, and people with kidney disease may need to limit potassium. [5]
• Allergy: a food allergy is possible with any food. For trouble breathing or swelling of the face or throat, call 911. See food allergy basics and emergency signs.
• Evidence in one line: eating more green leafy vegetables is linked to lower heart disease risk in observational studies, but trials of leafy greens on blood vessels and blood pressure have not shown a clear effect. [6]

What is in it (USDA values)

Raw Swiss chard, USDA FoodData Central item 169991 (SR Legacy). [1] USDA portion: 1 cup, 36 g.

% Daily Value uses the FDA 2016 Daily Values; values vary with variety, ripeness and storage. Per-cup figures are the per-100 g values scaled to 36 g.

USDA lists large amounts of lutein with zeaxanthin and of beta-carotene (3,647 mcg per 100 g), which are carotenoids (yellow-orange-green plant pigments). [1] The USDA data only measure the amounts. They do not show a health effect. Chard also contains nitrate, as other leafy vegetables do; a food-science study used chard powder as a natural nitrate source in sausage curing. [7] We found no chard-specific nitrate value from a source we could read, so we give none. Chard is also sodium-rich for a vegetable (213 mg per 100 g). [1]

What research says

Eaten as food vs taken as a supplement or extract. All the numbers above refer to the vegetable as food or to leafy greens as a group. We did not read any trial of chard extracts or powders. Do not assume results for another vegetable apply to chard, or that a nutrient-rich food treats a disease.

How much is a normal serving

• The USDA household portion in our data is 1 cup raw (36 g), or 1 leaf (48 g). [1]
• NHS counts 80 g of fresh, canned or frozen vegetables as one portion of the "5 A DAY"; WHO advises at least 400 g of fruit and vegetables a day for people over 10. These are public-health figures, not a prescription. [8][9]
• Cooking wilts the leaves, so a cooked cup holds far more leaf than a raw cup. We did not find a source on how cooking changes chard nutrients, so we make no claim.

Safety, allergy and medicines

• Warfarin and vitamin K. MedlinePlus says people on warfarin may need to limit vitamin K foods, names spinach, kale and collards among the main sources, and stresses a consistent amount day to day. Chard is not named there, but USDA shows it has more vitamin K per 100 g than a day's Daily Value several times over. [1][2] Ask the prescriber before changing how much chard you eat. See foods and medicine interactions.
• Oxalate and kidney stones. NIDDK (last reviewed May 2017) says people who have had calcium oxalate stones may want to avoid spinach, rhubarb and some other foods to lower urine oxalate, and to ask which stone type they had. It also says calcium does not cause calcium stones and can help block stone-forming substances. [3] The sources we read do not give an oxalate value for chard, so we cannot say how it compares with spinach.
• Oxalate kidney injury (a rare report). A 2026 case report describes a 59-year-old woman who developed acute kidney failure after one meal of freshly harvested Swiss chard during a diet change. A biopsy showed oxalate crystals in the kidney tubules; kidney function recovered with a low-oxalate diet. [4] One case does not show how common this is.
• Potassium and kidney disease. MedlinePlus lists leafy greens among potassium sources. In chronic kidney disease the kidneys may not remove extra potassium, and some medicines can raise potassium. People with kidney disease or on such medicines should ask their care team. [5] See kidney disease, potassium and oxalates.
• Nitrate. Leafy vegetables are a major dietary source of nitrate. A 2026 survey in Montenegro measured nitrate in chard and other leafy vegetables and estimated adult intake using an EFSA method; the abstract we read does not give a chard-only result. [10]
• Pregnancy. See foods in pregnancy: what official bodies advise. We did not find a chard-specific warning in sources we read.
• Allergy. We did not find a source on chard allergy, so we make no claim beyond the general emergency advice above.

Choosing, storing and food safety

• FDA advises rinsing produce under running water before eating, without soap or produce wash. Washing reduces bacteria but does not remove them all. [11]
• Refrigerate cut or packaged produce and keep perishable vegetables at 40 F (4 C) or below. Bagged greens labeled "pre-washed" or "ready-to-eat" need not be rewashed. [11]
• For more on frozen and canned options, see fresh, frozen and canned produce.

Related pages

• Leafy greens
• Beets
• Dietary nitrate in beets and leafy greens
• Foods and medicine interactions: vitamin K, grapefruit and others
• Foods, kidney disease, potassium and oxalates
• Fresh, frozen and canned produce