Health dangers When [oranges] are consumed in excess, the higher fiber level might interfere with digestion, producing stomach discomfort and even diarrhea. The vitamin C found in oranges is good for bones, but excessive amounts can be harmful to an adult's bone health. Too much vitamin C can lead to copper deficiency, which can cause nerve damage and blindness. Eating too many oranges could also increase the risk of developing kidney stones. The more common term for these small fruits is "citrus" fruits. They include oranges, lemons, limes, grapefruit, and tangerines. These fruits are very nutritious - full of vitamins A and C, potassium, magnesium, and phosphorus. They also have a lot of fiber, only about one ounce per fruit. However, like any other food, they can also be bad for your health if you eat too many of them. Most people don't eat enough citrus fruits to get sick from it. If you're concerned about possible digestive problems or diarrhea, then eating less than six ounces of orange juice or its equivalent every day might be a good idea. However, there is no evidence that shows that eating too many oranges will make you sick.