The best source of vitamin D is sunlight, as the skin can produce this essential nutrient when exposed to UV rays. However, dietary sources like fatty fish (such as salmon and mackerel), fortified dairy products, and egg yolks are also excellent options. For those with limited sun exposure or dietary restrictions, vitamin D supplements can be an effective way to ensure adequate intake. Maintaining sufficient vitamin D levels is crucial for bone health, immune function, and overall well-being.