Dietetic Technician Practice Test 2026 – All-in-One Guide to Exam Success!

The primary source of vitamin D is the combination of sunlight exposure and certain foods, particularly fatty fish. Vitamin D is unique among vitamins because the body can synthesize it when the skin is exposed to ultraviolet (UV) rays from the sun. This process helps maintain adequate levels of vitamin D in the body, which is crucial for bone health and the immune system.

Fatty fish, such as salmon, mackerel, and sardines, are among the few natural food sources rich in vitamin D, making them significant dietary sources. Other foods, such as fortified dairy products and cereals, may also contribute to vitamin D intake, but they do not match the effectiveness of sunlight and fatty fish in providing this nutrient.

Processed foods and whole grains typically do not contain significant amounts of vitamin D, which is why they are not considered primary sources. Animal proteins can vary in vitamin D content, but they are not the most reliable source compared to the sun and specific fish. Hence, the combination of sunlight exposure and fatty fish consumption is the dominant way to obtain vitamin D.