To naturally increase your vitamin B12 levels, it is important to include foods that are rich in B12 in your diet. Animal-derived foods such as meat (especially liver), fish (such as salmon and trout), shellfish, eggs, and dairy products (milk, cheese, and yogurt) are excellent sources of B12. For vegetarians and vegans, fortified plant-based milk alternatives (like soy milk or almond milk), fortified breakfast cereals, nutritional yeast, and B12 supplements are recommended. Additionally, incorporating fermented foods like tempeh, miso, or sauerkraut into your diet may promote B12 production by gut bacteria. However, it is advisable to consult with a healthcare professional or registered dietitian for personalized guidance and to determine the best approach to meet your B12 needs based on your dietary preferences and restrictions.