Vitamin C, Most of us are aware that vitamin C can help boost our immunity, protecting us against frequent colds and other diseases. What many people don’t realize, though, is vitamin C can help strengthen hair and help it grow. That’s partly because vitamin C helps the body produce collagen, a vital protein for healthy hair, skin, and nails. Additionally, vitamin C is considered an antioxidant that fights free radicals that damage body tissue. Free radicals have been known to damage hair, making it weak and brittle. If you notice your hair breaking a lot or shedding, it may be due to vitamin C deficiency.