How many calories are in boiled mustard leaves?

A typical portion (80 g, one of your five a day) gives 14 kcal. Per 100 g the figure is 17 kcal.

Yes. Mustard leaves, boiled in unsalted water have 26 mg vitamin C per 100 g, 33 % of the NRV, above the 30 % threshold for a “high in” claim.

Yes. Per 100 g, vitamin C goes from 71 mg raw to 26 mg boiled. Part of that is the vitamin or mineral itself changing, part is the change in water content.

By share of the daily reference intake: vitamin C (26 mg, 33 %), potassium (200 mg, 10 %) and calcium (80 mg, 10 %) per 100 g.

Every figure comes from the UK Composition of Foods Integrated Dataset (CoFID), 2021 edition, record 13-299, Mustard leaves, boiled in unsalted water, published by Public Health England under the Open Government Licence v3.0. Main data references: Haytowitz and Matthews (1984) Composition of foods: vegetables and vegetable products, raw, processed and prepared, Agriculture Handbook No 8-2, and Wu Leung et al. (1972) Food composition table for use in East Asia.. Values are per 100 g of the edible part; a portion is 80 g, one of your five a day, the usual UK portion for vegetables. Reference intakes follow Regulation (EU) 1169/2011 Annex XIII as retained in GB law; “source of”, “high in” and “low” follow Regulation (EC) 1924/2006, assessed per 100 g. Function lines are the authorised wording from the GB register of nutrition and health claims, credited to the nutrient. Energy is rounded to the whole kcal and kJ; other amounts to one decimal, or two below 1. A trace is shown as “trace” and never gets a figure or a badge; a nutrient never analysed is left off the page. We start from the dataset’s 2,887 records and keep 2,322: records weighed with bone, shell or skin, alcoholic drinks, infant foods, brand-named products, records with fewer than eight measured vitamins and minerals and near-identical variants are left out. Group context uses the 240 vegetables kept from the dataset; a rank counts only the foods with a measured figure for that nutrient. Food images are illustrations from Ingredient Atlas, released under CC0; they show the food, not the measured sample, and where no illustration of the exact food exists the nearest one is shown (here: Mustard Green). Checked 5 October 2026. Contains public sector information licensed under the Open Government Licence v3.0.