Kale

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By the Nutriveda editorial team · Updated 4 November 2026

Kale (Brassica oleracea, Acephala group) is a leafy cabbage that does not form a head, with curly or flat dark green leaves. 100 g of raw kale has 35 kcal and gives 390 µg of vitamin K, 93 mg of vitamin C, 2,870 µg of beta-carotene, 254 mg of calcium and 4.1 g of fibre. Like broccoli and cabbage, it is a cruciferous vegetable, and the calcium in it is absorbed well. Its one real catch is the very high vitamin K content, which matters for people who take warfarin.

Kale nutrition per 100 g and per portion

Nutrient	Raw, 100 g	Portion: 50 g raw (about 2 1/2 cups chopped)
Energy	35 kcal	18 kcal
Protein	2.9 g	1.5 g
Fat	1.5 g	0.7 g
Carbohydrate	4.4 g	2.2 g
of which sugars	1.0 g	0.5 g
Fibre	4.1 g	2.1 g
Vitamin K	390 µg	195 µg
Vitamin C	93.4 mg	47 mg
Vitamin A (RAE)	241 µg	121 µg
Beta-carotene	2,870 µg	1,435 µg
Calcium	254 mg	127 mg
Potassium	348 mg	174 mg
Manganese	0.92 mg	0.46 mg
Iron	1.6 mg	0.8 mg

Source: USDA FoodData Central, SR Legacy: “Kale, raw” (FDC 168421), checked 4 November 2026. The record’s measure is 1 cup = 21 g; the 50 g column is calculated. The record also lists 0.35 mg riboflavin and 62 µg folate per 100 g, and 0.38 g of ALA, the plant omega-3, out of 1.5 g of fat. Values rounded.

Raw kale is bulky and light: 50 g fills a salad bowl, and when you cook it, it shrinks to a few spoonfuls. That is worth remembering when you read portion sizes.

Glycemic index

Kale is not listed in the international GI tables (Atkinson 2008). With 4.4 g of carbohydrate per 100 g, almost all of it fibre and very little sugar, it adds almost no digestible carbohydrate to a meal. More on the topic in What is the glycemic index.

Health benefits: what the evidence says

• Vitamin K. Vitamin K is needed for normal blood clotting. NIH sets the adequate intake at 120 µg a day for men and 90 µg for women and lists one cup of raw kale at 113 µg. By the USDA record above, a 50 g portion gives about 195 µg, more than a day’s adequate intake.
• Calcium you can use. According to NIH, calcium from kale, broccoli and cabbage is absorbed about as well as calcium from milk, though a serving contains less of it. This sets kale apart from spinach, whose oxalates allow only about 5% of its calcium to be absorbed. For people who eat little dairy, kale is one of the more useful plant sources.
• Vitamin C. 100 g of raw kale has 93 mg, above the NIH adult RDA of 90 mg for men and 75 mg for women. NIH also notes that vitamin C improves the absorption of non-heme iron from plant foods; kale itself has 1.6 mg of iron per 100 g.
• Beta-carotene. Kale is rich in beta-carotene, which the body turns into vitamin A. NIH explains that the body absorbs about 10-30% of beta-carotene from foods and that cooking and heat treatment can increase how much is available, so both raw and cooked kale have their place.
• Cruciferous compounds. The US National Cancer Institute lists kale among the cruciferous vegetables that contain glucosinolates. These break down during chopping, chewing and digestion into compounds such as sulforaphane that are studied in the lab, while human studies on cancer risk have shown mixed results.
• Fibre. 50 g gives about 2 g of fibre towards the 25 g a day that EFSA considers adequate for normal bowel function in adults.

How to eat kale

• Prepare the leaves: pull the leaf away from the thick central stem, which stays tough, and tear or slice the leaves. Wash well, curly kale holds sand and soil in its folds.
• Massaged salad: sprinkle raw leaves with a pinch of salt, a squeeze of lemon and a spoon of olive oil and rub them with your hands for a minute or two until they darken and soften. Add apple, walnuts or pomegranate seeds.
• Sautéed: cook in a pan with olive oil and garlic for 3-5 minutes, with a splash of water if needed.
• In soups and stews: stir into bean, lentil or potato soups in the last 5-10 minutes; it holds its texture better than spinach.
• Kale chips: dry the leaves well, toss with a little oil and salt and bake at a low oven temperature (about 150 °C) until crisp, watching closely so they do not burn.
• Storage: keep unwashed in a bag in the fridge and use within a few days.

Who should be careful

• Warfarin (Coumadin). NIH warns that vitamin K can have a serious interaction with warfarin and that sudden changes in vitamin K intake can increase or decrease its effect. With 390 µg per 100 g, kale is one of the foods where this matters most. You do not have to give it up, but keep the amount steady from week to week, and talk to your doctor before you start daily kale smoothies or salads.
• Thyroid and iodine. NIH lists cruciferous vegetables among foods with goitrogens, substances that can interfere with how the thyroid uses iodine. According to NIH this is mainly a concern for people living in areas prone to iodine deficiency; with adequate iodine intake, reasonable amounts of these foods are not a concern.

Traditional view (Ayurveda)

Kale is a European leafy cabbage and does not appear in the classical Ayurvedic texts. In Usha and Vasant Lad’s food guidelines kale is favourable for Pitta and Kapha and on the list to avoid for Vata. This is a traditional view, not a clinical finding.

Recipes with kale

• Kale, apple and walnut salad

Related entries and articles

• Spinach – more iron, but calcium that is poorly absorbed
• Broccoli and Brussels sprouts – other cruciferous vegetables
• Red cabbage
• White beans – classic partner for kale in soups
• Which foods reduce inflammation naturally?
• Plant-based meals for weight loss

FAQ

Is kale better raw or cooked?

Both work. Raw kale keeps more vitamin C, which is sensitive to heat, while NIH notes that cooking can make beta-carotene more available. Massaging raw kale makes it softer and easier to eat, and a quick sauté or a few minutes in soup keeps most of its texture.

Can I eat kale if I take warfarin?

Usually yes, if the amount stays consistent. Kale is very rich in vitamin K, and NIH explains that sudden changes in vitamin K intake can change how warfarin works. Keep your weekly intake similar and discuss bigger changes with your doctor, who may adjust the dose.

Is kale bad for the thyroid?

Not for most people. Kale is a cruciferous vegetable, and NIH lists these among foods with goitrogens. NIH also states that for people with adequate iodine intake, reasonable amounts of such foods are not a concern; the risk is mainly where iodine deficiency is common.

Sources

1. USDA FoodData Central, SR Legacy: Kale, raw (FDC 168421). fdc.nal.usda.gov
2. NIH Office of Dietary Supplements: Vitamin K, Fact Sheet for Health Professionals. ods.od.nih.gov
3. NIH Office of Dietary Supplements: Calcium, Fact Sheet for Health Professionals. ods.od.nih.gov
4. NIH Office of Dietary Supplements: Vitamin C, Fact Sheet for Health Professionals. ods.od.nih.gov
5. NIH Office of Dietary Supplements: Vitamin A and Carotenoids, Fact Sheet for Health Professionals. ods.od.nih.gov
6. National Cancer Institute: Cruciferous Vegetables and Cancer Prevention. cancer.gov
7. NIH Office of Dietary Supplements: Iodine, Fact Sheet for Health Professionals. ods.od.nih.gov
8. EFSA NDA Panel (2010). Scientific Opinion on Dietary Reference Values for carbohydrates and dietary fibre. EFSA Journal 8(3):1462. efsa.europa.eu
9. Atkinson FS, Foster-Powell K, Brand-Miller JC. International Tables of Glycemic Index and Glycemic Load Values: 2008. Diabetes Care 2008;31(12):2281-2283. PMC
10. Lad U, Lad V. Food Guidelines for Basic Constitutional Types, from Ayurvedic Cooking for Self-Healing, 2nd ed. The Ayurvedic Institute. ayurveda.com

This page is for information only and is not medical or dietary advice.