Vitamin B-12: This vitamin is essential for cell growth and regeneration. Vitamin B-12 is in foods like beef, eggs, and poultry. You can also take a supplement. A lack of vitamin B-12 can lead to anemia, a common cause of hair loss. Iron is another essential nutrient for cell growth and regeneration. Its also necessary for carrying oxygen to cells. A lack of iron leads to anemia, a common cause of hair loss. Iron-rich foods include red meat, dark leafy greens, legumes, and fortified cereals. You can also take an iron supplement. Omega-3 Fatty Acids: These healthy fats are essential for several reasons, including maintaining healthy skin and hair. Foods rich in omega-3 fatty acids include salmon, walnuts, flaxseed oil, and avocados. You can also take an omega-3 supplement.