What is the main dietary source of vitamin D?

Vitamin D is essential for various bodily functions, including calcium absorption and bone health. The main dietary sources of vitamin D are fatty fish, such as salmon and mackerel, as well as fortified foods like milk and some plant-based milk alternatives. Sunlight exposure is also a critical factor because the skin synthesizes vitamin D when it is exposed to ultraviolet B (UVB) rays from the sun.

Fatty fish is a particularly rich source of vitamin D due to its high oil content, which naturally contains this vitamin. Fortified milk and some cereals have added vitamin D to help people meet their daily requirements, especially in regions with limited sunlight.

Other options, such as fruits and vegetables, sugary snacks, and grains, do not provide significant amounts of vitamin D. While fruits and vegetables are crucial for overall health and can provide various vitamins and minerals, they are not a notable source of vitamin D. Sugary snacks and beverages primarily offer empty calories with little to no nutritional value, and most varieties of rice and grains do not contribute meaningfully to vitamin D intake. Thus, the correct answer highlights the various ways individuals can obtain vitamin D through their diet and natural sunlight exposure.