Citrus fruits are a great source of which vitamin?

Citrus fruits are a great source of vitamin C. Oranges, lemons, limes, grapefruits, tangerines, and related fruits contain ascorbic acid, the biologically active form of this water-soluble vitamin.

Vitamin C helps the body make collagen, a protein important for skin, blood vessels, cartilage, bones, and wound healing. It also supports normal immune-system function and helps the body absorb non-heme iron from plant foods. Humans cannot manufacture vitamin C, so it must come from food or supplements.

Citrus became famous for its connection to scurvy, a serious vitamin-C deficiency that once afflicted sailors on long voyages. In 1747, British naval surgeon James Lind compared treatments for sailors with scurvy and found that oranges and lemons were especially effective. The Royal Navy later adopted citrus juice, leading to the nickname “limey” for British sailors and, eventually, Britons.

A common mix-up is assuming citrus is the only good source. Bell peppers, broccoli, strawberries, tomatoes, and potatoes also provide vitamin C.