Fat-soluble vitamins, such as A, D, E, and K, require dietary fats for optimal absorption. These vitamins dissolve in fats and oils, enhancing their absorption in the gastrointestinal tract. A diet low in healthy fats may impair the body's ability to utilize these essential vitamins, leading to deficiencies and associated health issues. For example, vitamin A is vital for vision and immune function, while vitamin D is crucial for bone health. Including sources of healthy fats, like avocados, nuts, and olive oil, can improve the bioavailability of these vital nutrients.