Supplement Safety & Efficacy Flashcards

A client reports taking selenium supplements daily at 400 mcg. What toxicity symptom should a nutrition coach watch for?

Answer: Hair loss, brittle nails, and garlic breath odor

Selenosis (selenium toxicity) presents with hair loss, nail brittleness, neurological symptoms, and a characteristic garlic-like odor from exhaled selenium compounds.

Bioavailability of a supplement refers to:

Answer: The proportion of an ingested nutrient that is absorbed and available for use by the body

Bioavailability describes the fraction of an ingested dose that reaches systemic circulation in an active form, which varies widely among supplement forms and individuals.

Which of the following supplement forms of magnesium is generally considered best for improving sleep and relaxation due to its high bioavailability and calming effects?

Answer: Magnesium glycinate

Magnesium glycinate (chelated with glycine) has high bioavailability, is gentle on the GI tract, and the glycine component also has calming, sleep-promoting properties.

A supplement claims to 'support immune function.' Under DSHEA regulations, this is classified as:

Answer: A structure/function claim that requires a disclaimer stating the FDA has not evaluated it

Structure/function claims describe how a nutrient affects normal body structure or function; manufacturers must notify the FDA within 30 days and include a disclaimer that the claim is not FDA-evaluated.

Kava (Piper methysticum) supplements have been associated with serious adverse effects on which organ system?

Answer: Hepatic system (liver damage)

Kava has been linked to severe hepatotoxicity, including cases of liver failure requiring transplantation, leading to regulatory warnings or bans in several countries.

A client wants to take high-dose zinc (50 mg/day) long-term for immune support. What nutritional consequence should be monitored?

Answer: Copper deficiency due to competitive absorption inhibition

Zinc and copper compete for the same intestinal transporter (metallothionein); chronic high-dose zinc supplementation can induce copper deficiency, leading to anemia and neurological problems.

Which of the following populations faces the highest risk of adverse effects from fat-soluble vitamin supplementation due to altered metabolism?

Answer: Individuals with chronic kidney disease taking high-dose vitamins A, D, E, K

Individuals with chronic kidney disease cannot adequately convert or excrete vitamin D metabolites, and impaired clearance increases the risk of toxicity from fat-soluble vitamins.