Vitamin A helps to protect skin from becoming dry. It is also helpful to the eyes. Without vitamin A, you cannot see well in darkness. Vitamin A is found in animal liver and yellow part of eggs. Sweet potatoes, carrots and other dark-colored fruit and vegetables have something that the body can change into vitamin A.

Vitamin B changes foods into energy and helps the heart and nerve system (血管) to work smoothly. Vitamin B also helps to produce red blood cells. Without it, we will be weak and will not grow. It is found in grains and other foods like beans, nuts, meat and fish.

Vitamin C is needed for strong bones and teeth, and for healthy blood vessels (血管). It also helps wounds to cure (愈合) quickly. The body stores little vitamin C, so we must get it in foods like oranges, tomatoes and cabbage.

Vitamin D increases the levels of calcium (钙) in the blood. Calcium is needed for verve and muscle (肌肉) cells to work normally, as well to build strong bones. Fish liver oil has vitamin D. In some countries, milk producers add vitamin D to milk so that it will be good for children.