One of the most famous vitamins — largely because a lack of it caused the notorious sailors’ illness, scurvy — is vitamin C. This vitamin is water-soluble and naturally present in high amounts in bell peppers, blackcurrants, parsley, and citrus fruits. Vitamin C is crucial for keeping the immune system strong¹ and aiding in energy production.² It’s also required for making collagen, a protein that’s key for connective tissues, bones, cartilage, and gums (which explains why sailors in the 1500s and 1600s often lost their teeth).⁷ Beyond this, vitamin C functions as an antioxidant,³ helping neutralize damaging molecules like free radicals and shielding the body’s cells from harm. For vegetarians, here’s a useful note: vitamin C improves the body’s ability to absorb iron from plant-based sources.