Which of the following is a significant source of Vitamin D?

Fatty fish is a significant source of Vitamin D because it naturally contains high levels of this essential nutrient. Fish species such as salmon, mackerel, and sardines are particularly rich in Vitamin D, which is important for bone health and immune function. This vitamin helps regulate calcium and phosphorus levels in the body, contributing to the maintenance of strong bones and teeth.

In contrast, bananas, whole grains, and red meat do not provide substantial amounts of Vitamin D. Bananas are known for their potassium content but provide minimal vitamins. Whole grains are a good source of fiber and other nutrients, but they lack Vitamin D. Red meat can contain small amounts of Vitamin D, depending on the animal's diet and exposure to sunlight, but it is not considered a significant source compared to fatty fish. Thus, recognizing fatty fish as a key dietary source of Vitamin D is crucial for maintaining proper nutrient levels in the body.