4. What are vitamins? What
arethe main vitamins needed
by humans?

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
Most vitamins are
(fundamental substances for
enzyme functioning) that not
produced by organism and must
obtained from the .

The main vitamins by humans
are A, C, D, , K, the vitamins
the B complex ( folic acid),
biotin pantothenic acid.