Lemons are healthy. Most of us associate lemons and citrus fruits with vitamin C, but that’s not all they have to offer. They’re low in sugar and lemons contain everything from vitamin B6, vitamin A, vitamin E, folate, niacin, thiamin, riboflavin, and pantothenic acid to minerals like calcium, copper, iron, magnesium, and phosphorus. They even contain more potassium than apples or grapes.