Vitamin capsules. Scattered capsules used for vitamin E or cod liver oil dietary supplements. Cod liver oil is a rich source of vitamins A and D. Vitamins are required by the body's cells for normal growth and functioning. They are only required in trace amounts and can easily be obtained by eating a balanced diet. Vitamin supplements are useful for people who are not eating properly or require additional vitamins due to illness or pregnancy. Photograph of Epo pills.