A group of 50 adult male humans were in a clinical study to determine how much niacin is toxic.During the first two weeks of the study,members of the group consumed only a formula diet that was nutritionally complete,except it contained 24 mg niacin,which is 1.5 times the RDA for niacin (males).At that point in the study,all members reported feeling fine,and they could function normally.During the next week,they were given a formula that contained 48 mg niacin.Within a few days of consuming this formula,90% of the participants reported feeling ill,and they complained of having upset stomachs and reddened facial skin.At that point,researchers gave the subjects a formula that contain 16 mg niacin.After a week of consuming the new formula,all participants reported feeling well again.Based on this information,the researchers concluded that the

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Quizplus · Accepted Answer

The study showed that a consumption of 48 mg of niacin caused 90% of the participants to feel ill, indicating that this was likely the upper limit (UL) of safe niacin consumption. Therefore, choice B is the best answer. The study did not provide enough information to determine the Estimated Energy Requirement (EER) or Average Macronutrient Distribution Range (AMDR) for niacin, and the fact that the participants felt well consuming 16 mg of niacin does not necessarily mean that this is the human requirement for niacin.

A Group of 50 Adult Male Humans Were in a Clinical