Leeks (Allium ampeloprasum) are a versatile, low-calorie vegetable that fits easily into soups, stir-fries, and braised dishes. While leeks are not the most concentrated source of vitamin C, they make a steady contribution to your daily intake when eaten regularly. This calculator converts any serving of leeks into milligrams of vitamin C and a percentage of the recommended Daily Value, using standard food-composition data for raw and cooked leeks. It is ideal for anyone tracking micronutrients, planning balanced meals, or simply curious about how leeks compare with more famous vitamin C foods.
Enter the amount of leeks you plan to eat, choose the serving unit (grams, ounces, cups, or whole leeks), and select raw or cooked preparation. The tool then estimates total vitamin C, shows the percentage of the Daily Value that amount covers, and tells you how many oranges it would take to supply the same vitamin C. All calculations are based on widely used reference values, making this a practical, fast addition to your nutrition toolkit.
⚙️ Serving Details
Cup and whole-leek weights are for raw leeks; enter grams for cooked leeks.
How It Works
This calculator uses vitamin C density values from standard food-composition databases for raw and boiled leeks. Raw leeks contain about 12 mg of vitamin C per 100 g, while cooked, drained leeks contain about 4.2 mg per 100 g. The tool first converts whatever serving size you enter into grams, then applies the correct density for the preparation you select.
The Daily Value percentage is based on the FDA's adult reference of 90 mg of vitamin C per day. The orange equivalent uses a medium orange reference of 69.7 mg of vitamin C.
Step-by-Step Guide
- Enter the amount of leeks you will eat.
- Choose the unit that matches your measurement: grams, ounces, cups, medium leeks, or large leeks.
- Select raw or cooked preparation.
- Click Calculate Vitamin C to see total milligrams, Daily Value percentage, orange equivalent, and how much leek would be needed to reach 100% DV.
- Use Reset to clear the form, or tap a quick-select button to try a common serving size.
Reference Values
| Item | Value |
|---|---|
| Raw leeks | 12 mg vitamin C per 100 g |
| Cooked leeks (boiled, drained) | 4.2 mg vitamin C per 100 g |
| 1 cup raw chopped leeks | ≈ 89 g |
| 1 medium raw leek | ≈ 89 g |
| 1 large raw leek | ≈ 140 g |
| Adult Daily Value for vitamin C | 90 mg |
| Medium orange | ≈ 69.7 mg vitamin C |
Worked Examples
Example 1: A 100 g serving of raw leeks provides 100 × 12 ÷ 100 = 12 mg vitamin C, which is 12 ÷ 90 × 100 = 13% DV. To match that amount you would need about 0.17 of a medium orange.
Example 2: If a recipe uses 1 cup of cooked leeks and you enter 89 g with the cooked option, the result is 89 × 4.2 ÷ 100 ≈ 3.7 mg, or about 4% DV. This shows why lightly cooking leeks and keeping the cooking water for soups can preserve more of the vitamin.
Tips for Using This Tool Well
- Weigh leeks on a kitchen scale for accurate portions; visual estimates of chopped vegetables can vary by 25% or more.
- If a recipe calls for 1 sliced leek, most medium leeks yield about 85–95 g of trimmed edible portions, so 1 medium leek is a reasonable default.
- Use the raw option when logging leeks that will be added to a cold salad or used as a garnish, and the cooked option for hot dishes where leeks are simmered.
- Remember that vitamin C values in packaged products can differ; if you have a nutrition label, enter that value manually.
Frequently Asked Questions
Are leeks a good source of vitamin C?
Leeks are a moderate source. A 100 g raw portion supplies about 13% of the Daily Value, which is helpful but well below the amounts found in citrus fruits, kiwi, or bell peppers. Still, leeks contribute meaningful vitamin C when eaten regularly as part of a varied diet.
Why does cooking lower the vitamin C content?
Vitamin C can be destroyed by heat, light, and oxygen, and it dissolves in water. Boiling leeks both leaches vitamin C into the cooking water and exposes it to prolonged heat, which is why the cooked value in this calculator is lower.
Should I use the raw or cooked value for a stir-fried leek?
Stir-frying is usually quick, so vitamin C loss is smaller than with boiling. The cooked value in this tool is based on boiled, drained leeks, so a stir-fried batch may fall somewhere between the raw and cooked estimates. When in doubt, use the cooked value for a more conservative estimate.
Additional Resources
- USDA FoodData Central — search for "leeks" to see detailed nutrient profiles for raw and cooked forms.
- NIH Office of Dietary Supplements: Vitamin C — evidence-based information on vitamin C intake and health.
- FDA Nutrition Facts Label — current Daily Value reference amounts for nutrition labels.