I think that oxygen is needed , because it helps elevate the blood level and help oxygen spread to your brain/ heart.
To complete the thought of the sentence, the word that will fit that blank is "enzymes". Vitamins work with enzymes to initiate chemical reactions within cells. Some enzymes in our body needs other components like vitamins to enable reactions to happen.
Answer: HEMORRHOIDS
Explanation: The DESCENDING COLON is the lower portion of the Large intestine,it is the place for the storage of side products of digestion,which are to be emptied through the ANUS.
Hemorrhoids are swollen or enlarged veins in the RECTUM
or ANUS which can be internal or external, about 75% of adults are expected to have had or has the swollen vein or veins called HEMORRHOIDS.
Consumption is when you go over the limit of alcohol and it can affect your health