There are many vitamins out there and it can be overwhelming knowing what vitamin would be best for your health, so here is a brief overview! Vitamin A is for eye health. Vitamin B1 breaks down sugar, B2 and B3 help cells grow, B5 produces energy and hormones, B6 helps form red blood cells, B7 helps the skin, hair, and nails grow, B9 helps make DNA and RNA, and B12 helps the nervous system. Vitamin C strengthens blood vessels and the immune system. Vitamin D is essential for bone health. Vitamin E is an antioxidant. Finally, Vitamin K helps your blood clot.