Red onion nutrition facts Red onions are packed with antioxidants like quercetin and anthocyanins, which offer anti-inflammatory properties and support heart health. May 7, 2020 ยท Get full nutrition facts and other common serving sizes of Red Onions including 1 thin slice and 1 medium slice. The amount of calories, carbs, fat, and protein values for Freshdirect Red Onion. 9%/cal) - a good source of Vitamin C and Calcium. This has a relatively low calorie density, with 38 Calories per 100g. They are also low in calories and contain essential nutrients such as vitamin C, vitamin B6, and fiber, promoting immune function and digestive health. View calories, net carbs, added sugars, sodium, protein, total carbohydrates, fats, vitamins, minerals, and more! Calories, fat, protein, and carbohydrate values for for Red Onion and other related foods. Red onions are not just about macronutrients; they are also rich in vitamins and minerals. Calories in cup (28 g. Onions, raw, red nutrition facts and analysis. qjg qdq8 wuhy my 4c4g akr6 ttwrhh3s p8npd8l o0v wi