Source: USDA FoodData Central · Raw · Data verified by CaloriesCalc
* % Daily Value based on a 2,000 kcal diet.
| Nutrient | Amount | % Daily Value | Bar |
|---|---|---|---|
| Vitamin C | 53.0 mg | 59% | |
| Potassium | 138 mg | 3% | |
| Vitamin B6 | 0.08 mg | 5% | |
| Folate (B9) | 11 µg | 3% | |
| Thiamine (B1) | 0.04 mg | 3% | |
| Calcium | 26 mg | 2% | |
| Magnesium | 8 mg | 2% | |
| Phosphorus | 16 mg | 2% | |
| Iron | 0.6 mg | 3% | |
| Vitamin E | 0.15 mg | 1% |
| Weight | Calories | Carbs | Protein | Fat |
|---|
| Serving | Weight | Calories | Carbs | Net Carbs | Fat |
|---|---|---|---|---|---|
| 1 tbsp lemon juice | 15ml | 4 kcal | 1.3g | 1.2g | 0.0g |
| 1 wedge (1/8 lemon) | 10g | 3 kcal | 0.9g | 0.7g | 0.0g |
| ⭐ 1 medium lemon (flesh) | 108g | 31 kcal | 10.1g | 7.1g | 0.3g |
| 1 large lemon (flesh) | 139g | 40 kcal | 13.0g | 9.1g | 0.4g |
| 1 oz | 28g | 8 kcal | 2.6g | 1.9g | 0.1g |
Lemon is 89% water with only 2.5g of natural sugar per 100g. The tartness comes from high citric acid content (~5-8g/100g) rather than sugar. Net carbs are 6.5g per 100g — making lemon one of the lowest-sugar citrus fruits.
Lemons provide 53mg of vitamin C per 100g — 59% of the daily value. Beyond immune support and collagen synthesis, vitamin C from lemon has a specific practical benefit: it dramatically increases absorption of non-haem iron (iron from plant foods). Research suggests that consuming lemon juice with plant-based iron sources (beans, lentils, spinach) can increase iron absorption by 2–6 times. This makes lemon juice an important dietary tool for vegetarians and vegans who rely on plant iron.
Lemon juice is one of the most concentrated dietary sources of citric acid. Citric acid binds to calcium in urine, inhibiting crystal formation and preventing the most common type of kidney stone (calcium oxalate). Research consistently shows that people who drink lemon juice regularly have lower rates of kidney stone formation. A 2007 study found that lemon juice was as effective as prescription potassium citrate for increasing urinary citrate levels in kidney stone patients.
Like all citrus fruits, lemons contain hesperidin — a flavonoid concentrated in the peel and white pith. Hesperidin improves blood vessel flexibility (endothelial function), reduces LDL oxidation, and has anti-inflammatory effects. While most of the hesperidin is in the peel rather than the juice, grated lemon zest added to food can significantly increase intake. Lemon zest contains up to 150mg of hesperidin per tablespoon.
Despite being acidic (pH ~2-3), lemon juice has an alkalising effect on urine once metabolised. The citrate and mineral content is metabolised to bicarbonate, which raises urine pH. The urinary alkalisation from lemon is real and beneficial for kidney stone prevention, even if broader claims about body pH are unfounded.
Nutrition values sourced from USDA FoodData Central. Not medical advice.