What is a possible physical sign of niacin deficiency?

A possible physical sign of niacin deficiency includes symptoms like hyperpigmentation and skin flushing. Niacin, also known as vitamin B3, is crucial for various metabolic processes, and its deficiency can lead to a condition called pellagra. Pellagra is characterized by the three "Ds": dermatitis, diarrhea, and dementia. One notable skin manifestation of niacin deficiency is a pigmented rash that typically appears on sun-exposed areas, which can lead to increased pigmentation.

Skin flushing occurs due to niacin's role in vasodilation, which can be heightened in individuals with low levels of the vitamin. This flushing response is often a temporary and benign effect when niacin is consumed in adequate amounts or given as a supplement.

The other options refer to signs of deficiencies related to different vitamins. Night blindness and dry membranes are typically linked to vitamin A deficiency. Scaliness and peripheral neuropathy can indicate deficiencies in other B vitamins, particularly B6 or B12. Each nutrient plays its unique role in the body, and the signs of their deficiencies differ significantly. Therefore, while "All of the Above" may seem like a comprehensive choice, the specific signs mentioned for niacin make hyperpigmentation and skin flushing the most accurate association with its deficiency.