how many vitamins are known to be required in the diet of human beings?
How many different kinds of amino acids make up proteins?: 20 259. How many hydrogen atoms are attached to each carbon adjacent to a double bond?: 1 260. How many minerals are known to be required in the diet of human beings?: 16 261. How many subgroups comprise the vegetable food group?: 5 262. How many vitamins are known to be required in the diet of human beings?: 13 263. If a group of people consumed an amount of protein equal to the average requirement for their population group, what percentage would receive insufficient amounts?: 50 264.