ISSA Nutritionist Practice Exam

Which of these hormones is most likely responsible for negative kidney health outcomes associated with low water intake?

1. Cortisol

2. Arginine vasopressin

3. Aldosterone

4. Angiotensin II

The correct answer is: Arginine vasopressin

Arginine vasopressin is the hormone primarily responsible for regulating water balance in the body. When water intake is low, the body needs to conserve water to maintain hydration and normal physiological functions. In response to dehydration or low water intake, the hypothalamus stimulates the release of arginine vasopressin from the posterior pituitary gland. This hormone acts on the kidneys to promote water reabsorption in the collecting ducts, reducing water loss in urine. However, consistently low water intake can lead to its overproduction, which may result in concentrated urine and put additional stress on the kidneys. This stress can ultimately contribute to negative health outcomes, such as kidney stones or chronic kidney disease, as the kidneys struggle to function optimally under conditions of dehydration. The other hormones mentioned also play roles in kidney function but do not primarily govern water retention in the same direct way as arginine vasopressin. Cortisol is mainly involved in stress response and has a more complex role in metabolic processes, whereas aldosterone primarily regulates sodium and potassium levels rather than directly influencing water reabsorption. Angiotensin II plays a role in blood pressure regulation and fluid balance but is part of a broader hormonal cascade triggered in response to low blood volume rather than a direct