Vitamins and supplements that promote hair growth and reduce hair loss include biotin (vitamin B7), which supports keratin production and strengthens hair. Vitamin D helps create new hair follicles, while vitamin E provides antioxidant protection to maintain scalp health. Iron prevents hair loss by improving oxygen delivery to hair follicles, and zinc supports hair repair and growth. Omega-3 fatty acids nourish hair and reduce inflammation, while collagen supplements improve hair strength and elasticity. Consult a healthcare provider before starting any supplement regimen to ensure it meets your needs.