1. under what circumstances might vitamin and/or mineral supplements be recommended?

A vitamin or mineral supplement might be recommended if someone has a deficiency. For example people with and iron deficiency might be given a supplement so that they can remain healthy.

for some vitamins and minerals can be recommend when the body does not have much of the certain thing like if your body is short of vitamin E or vitamin C i would get the vitamin and take just enough that you body is healthy

hope this helped

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answer; (b) i believe its metabolic rate of the patient; plz check first