Kohlrabi: What It Is, USDA Nutrition and How to Eat It

Kohlrabi is a pale green or purple vegetable that looks like a small alien planet: a round, swollen stem that grows just above the soil, with leafy stalks sprouting from its sides. It belongs to the same species as cabbage and broccoli, Brassica oleracea, and tastes like a milder, sweeter, crunchier cross between a broccoli stem and a radish. In USDA data, one raw cup supplies most of a day’s Daily Value for vitamin C and a good share of fiber for very few calories. Below is what kohlrabi is, the kohlrabi nutrition numbers from USDA, how it compares with its relatives, what the research on its plant compounds does and does not show, and how to eat kohlrabi raw or cooked.

Peptide Labs does not sell kohlrabi or kohlrabi products. This article is general nutrition information, not medical advice.

What is kohlrabi?

Kohlrabi is a cultivated form of the wild cabbage species. Scientists name it Brassica oleracea var. gongylodes, which puts it in the same species as cabbage, broccoli, cauliflower, kale, Brussels sprouts and collards, each bred for a different part of the plant. In kohlrabi, the part that swells is the stem just above the ground, so despite looking like a root vegetable it is not a root at all.

• Green and purple kinds: the skin may be pale green or purple, but the flesh inside is creamy white in both, and the taste is very similar.
• The bulb: crisp, juicy and mildly sweet with a light peppery bite; smaller bulbs tend to be more tender.
• The leaves: edible, with a flavor close to collards or kale, and are often sold attached to the bulb.

Because it is a cruciferous vegetable, kohlrabi often lands in the same recipes and grocery aisles as cabbage and turnips. Our leafy greens guide and kale guide cover the leafy members of the family.

Kohlrabi nutrition: USDA values per cup

These figures come from the USDA FoodData Central SR Legacy database, using USDA’s own cup weights, with percent Daily Value (DV) based on FDA reference amounts.

Three things stand out. First, vitamin C: in USDA data a cup of kohlrabi gets close to a full day’s Daily Value, which is why it shows up in our guide to vitamin C foods. Second, fiber: raw kohlrabi is a useful fiber source for a watery vegetable; see our fiber-rich foods list and daily fiber guide for context. Note that per 100 grams the boiled entry lists 1.1 grams of fiber against 3.6 grams for raw in USDA SR Legacy; we report the values as published. Third, potassium and copper are present in modest amounts, and our potassium foods guide shows where kohlrabi sits among other vegetables.

Kohlrabi vs cabbage, broccoli, cauliflower and turnip

Per 100 grams of the raw vegetable, here is how kohlrabi compares with its cruciferous relatives in USDA SR Legacy.

Kohlrabi has the most fiber in this group per 100 grams, more vitamin C than cabbage or cauliflower and nearly as much potassium as broccoli. The surprise is vitamin K: USDA lists almost none for kohlrabi, while cabbage and broccoli are rich sources. That matters for people who take warfarin, who are advised by NIH and MedlinePlus to keep their vitamin K intake consistent from week to week, because sudden changes can alter how the drug works. Our vitamin K foods guide explains that advice; USDA has no separate entry for kohlrabi leaves, so do not assume they are low in vitamin K too. For a lower-carbohydrate vegetable list, see our low-carb foods guide.

What research says about kohlrabi

There are no human trials testing kohlrabi for any health outcome. What exists is chemistry and lab work, mostly on the sulfur-containing compounds found throughout the cabbage family.

• Glucosinolates (2025, Food Chemistry): researchers analyzed nine kohlrabi tissues. Leaf tissues were rich in glucoraphanin, while the bulb contained more glucoerucin. An enzyme in the plant, myrosinase, breaks glucosinolates down into isothiocyanates, unless other plant proteins steer the reaction toward less active compounds.
• Isothiocyanates (2026, Natural Product Research): a lab method study measured the isothiocyanates erucin and phenethyl isothiocyanate in raw and fermented kohlrabi. It shows the compounds are there; it does not show any effect in people.
• Fermented kohlrabi: industrially fermented kohlrabi is produced in China, and recent papers profile its metabolites. As with sauerkraut, check the Nutrition Facts label of any fermented vegetable for sodium; our fermented foods guide covers what is known about ferments in general.

Headlines that link cruciferous vegetables to strong health effects usually come from lab studies or from observational studies of whole diets, not from kohlrabi itself. The honest takeaway is that kohlrabi is a low-calorie, high-vitamin C vegetable with interesting chemistry and no direct human evidence of specific benefits.

Kohlrabi, goitrogens and the thyroid

The NIH Office of Dietary Supplements notes that cruciferous vegetables such as cabbage, broccoli and cauliflower contain goitrogens, substances that can interfere with iodine uptake by the thyroid and worsen iodine deficiency. The same fact sheet says this is mainly a concern in areas prone to iodine deficiency, and that for most people who get enough iodine and eat a variety of foods, reasonable amounts of these foods are not a concern. If you have a thyroid condition, ask your clinician; our iodine guide covers iodine sources and cautions.

How to eat kohlrabi

• Choosing: look for firm, heavy bulbs with no cracks; smaller ones are usually more tender. Fresh-looking leaves are a sign of a recently harvested bulb.
• Storing: cut off the leaves and refrigerate them and the bulb separately; the leaves wilt much faster.
• Peeling: trim the stalk stubs and peel away the fibrous outer skin with a knife or sturdy peeler until you reach the pale, crisp flesh.
• Raw: slice into sticks for dips, grate into slaws or cut into thin rounds for salads; it keeps its crunch well.
• Cooked: roast cubes until golden, saute slices, add to soups and stir-fries, or mash with potatoes. It turns sweeter and softer as it cooks.
• Leaves: saute, braise or add to soups the way you would collards or kale.

Kohlrabi is not one of the nine major food allergens that US labels must declare, though any food can cause a reaction in some people. If you are looking for another crunchy, versatile vegetable, our sibling guide to green beans covers a very different nutrient profile, including a lot more vitamin K.

Frequently Asked Questions

Questions about a label? Contact us or read our Buyer’s Guide. Food comes first; follow the label and ask a healthcare provider before starting a supplement, especially if you take medicines, are pregnant or have a food allergy. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Last reviewed October 2026.

Related guides: Green Beans: Nutrition Facts, Health Notes and Safety, Cabbage Benefits and Nutrition: Red vs Green Cabbage, Foods High in Vitamin C: USDA List of Fruits and Vegetables.