Vitamins are complex chemical substances (find) in many foods. The human body needs them for health and
(grow). The body makes some vitamins, but usually in amounts too small to meet its needs.
vitamins are not made in the body. These must __
_(supply). No one knows
(exact) how all vitamins work. Doctors do know that vitamins have very special uses.
, One vitamin cannot take the place of another. The steady absence of one vitamin causes a deficiency disease. Rickets, scurvy, and pellagra are examples_
__ deficiency diseases.
It is best to get vitamins eating the foods in which they occur. There are also pills that contain a single vitamin _
_a combination of vitamins. People should ask their doctors_
__they take any vitamin pills.