Source of vitamin C
A lack of vitamin C (ascorbic acid) [1] can cause feting scurvy, a now-rare illness that was sometimes treated with lemon juice. The immune system is generally thought to benefit from vitamin C, but findings are still mixed. According to one study, vitamin C may lessen the duration of cold symptoms and may divide the risk of getting the common cold between persons exposed to brief periods of extremely high body stress (such as marathon runners), even if it did not prevent normally healthy people from getting the illness.
Citrus juice from lemons contains vitamin C, a direct antioxidant that helps protect cells from harmful free radicals. Additionally, vitamin C plays a part in helping your body produce hormones, absorb iron, and synthesize collagen.