Grapefruit is a great source of vitamins C and A along with potassium, thiamin, folate, and magnesium. The anti-oxidants and phytochemicals like limonene, limonin, nomolin, and naringenin present in grapefruits reduces the risk of lung and colon cancer. Salicylic acid present in this citrus fruit breaks down the calcium build up in joints thereby relieving arthritis pains. The Vitamin C present in grapefruit also increases the release of citric acid in body thereby lowering the chances of calcium kidney stones. The best way to juice grapefruit is by peeling of the yellow outer part while retaining as much of the white pith as possible and dropping the pieces in the juicer.