Yellow onions are the everyday cooking onion, with a stronger flavour than red or white types. They provide quercetin, sulphur compounds, prebiotic fibres and small amounts of vitamin C.
Slow cooking develops sweetness but reduces vitamin C and some sulphur compounds; using both raw and cooked in a dish keeps a balance.
Where Onions, yellow, raw Stands Out
Macronutrients per 100g
Vitamins & Minerals
| Nutrient | Per 100g | % Daily Value* | Level |
|---|---|---|---|
| Potassium | 182 mg | 9% | |
| Phosphorus | 34.0 mg | 5% | |
| Calcium | 15.0 mg | 2% | |
| Magnesium | 9.00 mg | 2% | |
| Vitamin C | 8.20 mg | 10% | |
| Iron | 0.280 mg | 2% | |
| Zinc | 0.200 mg | 2% | |
| Manganese | 0.144 mg | 7% | |
| Copper | 0.035 mg | 4% | |
| Selenium | 0.000 µg | 0% | |
| Iodine | 0.000 µg | 0% | |
| Glucose (dextrose) | 2.31 g | — | |
| Fructose | 1.91 g | — | |
| Sucrose | 1.60 g | — | |
| Biotin (Vitamin B7) | 0.000 µg | 0% |
* % Daily Value is the proportion of an adult
EU Nutrient Reference Value (NRV) supplied by 100g of this food.
NRVs are the labelling standard — the same basis as the “%RI” figures printed on
food packaging — so these percentages are directly comparable with a shop label.
They are a single adult figure and do not vary by age or sex, which is why they
sometimes differ from UK dietary reference values: the NRV for vitamin C is 80mg
where the UK RNI is 40mg. When Nutriofia assesses your own intake in the
reports and trackers, it uses the age- and sex-specific UK values instead.
Fibre is shown without a percentage. Our fibre values use the UK
Englyst NSP method, while the published 30g daily goal is an AOAC figure — the two
are measured differently and a single percentage would mislead.
How we source and normalise our data →
Phytochemicals
Bioactive plant compounds — not classified as essential nutrients but associated with a range of health benefits.