Chapter 16 — Quiz

Twenty-one questions. Attempt before opening.

Multiple Choice

1. Under DSHEA 1994, supplements are regulated:

  • a) Like drugs — pre-market approval for safety and efficacy
  • b) More like food — no pre-market approval; the FDA must demonstrate harm after marketing
  • c) Not at all
  • d) By the manufacturer's own independent auditors
Answer **b.** The burden of proof runs **backwards** relative to drugs — which explains proprietary blends, structure/function claims, adulteration reaching shelves, and why "if it were dangerous it wouldn't be sold" is precisely inverted. **The safety data is generated by consumers.**

2. "Supports immune health" is:

  • a) Marketing fluff obscuring a stronger claim
  • b) A structure/function claim — and the strongest thing the product is legally permitted to say without evidence
  • c) A disease claim
  • d) A regulated efficacy statement
Answer **b.** The vocabulary — *supports, promotes, helps maintain* — is legally selected, not vague by accident. **A product that could say "reduces the risk of X" would say it.**

3. Third-party certification (NSF, Informed Sport, USP) verifies:

  • a) That the supplement works
  • b) That the contents match the label and contain nothing they shouldn't
  • c) FDA approval
  • d) Clinical efficacy for the stated claim
Answer **b.** A lower bar than people assume and a higher one than the baseline. ⚠️ **Non-negotiable for tested athletes** — strict liability applies and "it was in my supplement" is not a defence.

4. Which product categories are most commonly found adulterated with undeclared pharmaceuticals?

  • a) Multivitamins, calcium, fish oil
  • b) Weight loss, sexual enhancement, bodybuilding
  • c) Probiotics, fiber, protein powder
  • d) Herbal teas
Answer **b.** Sibutramine, sildenafil analogues, and anabolic steroids respectively. ⚠️ A person on nitrates unknowingly taking a sildenafil analogue is at risk of a severe hypotensive event.

5. Creatine monohydrate works by:

  • a) Increasing testosterone
  • b) Increasing muscle creatine phosphate stores — the fastest ATP-regenerating system, covering very short maximal efforts
  • c) Increasing protein synthesis directly
  • d) Improving oxygen delivery
Answer **b.** A **buffer, not a fuel** — a rechargeable battery covering the gap before slower systems arrive. Which is why it helps the fifth heavy rep and does essentially nothing for a marathon.

6. The recommended creatine protocol is:

  • a) 20 g/day loading forever
  • b) ~3–5 g/day of monohydrate, consistently, no loading required
  • c) 500 mg of a "buffered advanced" form
  • d) Only on training days
Answer **b.** ⚠️ Third-party certified, and **skip every "advanced," "buffered" or "liposomal" form** — they cost more and haven't outperformed plain monohydrate. Cost: **$0.10–$0.20/day.**

7. Caffeine's effective ergogenic dose is approximately:

  • a) 1 mg/kg
  • b) 3–6 mg/kg, about an hour before exercise
  • c) 15 mg/kg
  • d) There is no established dose
Answer **b.** 🟢 One of the best-supported ergogenic aids there is — and available as coffee. ⚠️ Note the caveat: caffeine later in the day degrades sleep, which costs more than the session gained.

8. A "proprietary blend" means:

  • a) A patented formulation with proven synergy
  • b) Total weight is declared but individual ingredient amounts are not — so no dose can be assessed
  • c) A blend approved by the FDA
  • d) All ingredients are present at clinical doses
Answer **b.** Which permits **fairy dusting** — an ingredient present in enough quantity to appear on the label and insufficient quantity to do anything. **Treat unassessable as unsupported.**

9. High-dose biotin interferes with troponin assays because:

  • a) It damages cardiac muscle
  • b) Many immunoassays use a biotin–streptavidin binding system, and free biotin competes with it
  • c) It thins the blood
  • d) It raises creatinine
Answer **b.** ⚠️ **In sandwich-format assays the result is falsely LOW** — the dangerous direction, because it produces false reassurance. The FDA issued safety communications in 2017 and 2019, noting a reported death associated with a falsely low troponin.

10. Creatine raises serum creatinine because:

  • a) It damages the kidneys
  • b) It's a laboratory artefact of creatine metabolism — not kidney injury
  • c) It causes dehydration
  • d) It increases protein breakdown
Answer **b.** Long-term studies in healthy people haven't found the feared kidney damage. ⚠️ **But tell your clinician you take it before a kidney function test**, or you'll be investigated for something you don't have.

11. The most dangerous common supplement–drug interaction is:

  • a) Vitamin C and iron
  • b) St John's Wort — a potent CYP3A4 inducer affecting contraceptives, warfarin, immunosuppressants, antiretrovirals
  • c) Magnesium and calcium
  • d) Vitamin D and calcium
Answer **b.** ⚠️ Contraceptive failure and transplant rejection are documented consequences — from a product sold on a pharmacy shelf with no point-of-sale warning.

12. "Pharmaceutical grade" on a supplement label means:

  • a) Manufactured to drug standards and FDA-inspected
  • b) ⚠️ Nothing — it has no legal definition for supplements
  • c) Third-party certified
  • d) USP verified
Answer **b.** An unregulated marketing term. Compare with **NSF Certified for Sport**, **Informed Sport** and **USP Verified**, which mean something specific.

13. What do all six nutritional ✅ verdicts in Part III have in common?

  • a) They're all vitamins
  • b) Each corrects a measured deficiency or meets a genuinely elevated requirement in a defined group
  • c) They're all expensive
  • d) They all work for everyone
Answer **b.** Folic acid preconception · B12 for vegans and malabsorption · vitamin D in the deficient · iron in the iron-deficient · iodine in pregnancy · ORS in illness. **None improves a replete person.** Creatine and caffeine are the deliberate exceptions — ergogenic rather than nutritional.

True / False

One-line justification.

14. If a supplement were dangerous, it wouldn't be on the shelf.

Answer **False, and precisely backwards.** Under DSHEA there is no pre-market approval; the FDA must demonstrate harm *after* marketing, using evidence generated by people already taking it. **Shelf presence carries no safety information.**

15. "It's natural, so it's safe."

Answer **False.** Digitalis, atropine, ricin, amatoxins and nicotine are all natural; many pharmaceuticals are plant-derived. **And supplements are frequently far more concentrated than any food** — which is the mechanism by which a traditionally safe plant becomes a hepatotoxin (green tea extract, kava).

16. Third-party certification means the supplement has been shown to work.

Answer **False.** It verifies **contents match label and contain nothing banned**. It says nothing whatever about efficacy — which is the only quality signal available, and a much narrower one than the mark implies.

17. Walt's multivitamin was harmless even though it didn't help.

Answer **False.** It supplied **the appearance of coverage** — his family and clinicians knew he took a multivitamin containing B12 — which closed a question that should have stayed open while a symptomatic, correctable deficiency progressed for two years.

18. Creatine should be taken with a loading phase and in an "advanced" form for best results.

Answer **False on both.** ~3–5 g/day of plain **monohydrate**, consistently; loading accelerates saturation but isn't required. "Advanced," "buffered" and "liposomal" forms cost more and haven't outperformed monohydrate — which is the clearest example of the premium-form pattern in the chapter.

Short Answer

19. Explain the two pipelines from §16.1 and why the direction of the burden of proof explains the rest of the chapter.

Answer **The drug pipeline** has gates — preclinical, Phase I, II, III, regulatory review — and the burden runs **from manufacturer to regulator**: *demonstrate this works and is safe.* Most candidates die in it. **The supplement pipeline** has one meaningful gate and it is at the **end**: idea → formulate → manufacture → **sell** → and only then, if enough harm accumulates and is reported and investigated, may the FDA act. The burden runs **from regulator to product, after the fact**. **That reversal explains everything downstream:** proprietary blends are legal because nobody has to justify a dose; "supports immune health" is the ceiling of permitted language; adulterated products reach shelves because nothing checks beforehand; third-party certification exists as a *voluntary market response to a regulatory gap*; and **"if it were dangerous it wouldn't be sold" is inverted** — the safety data is generated by consumers, and Walt was one of them.

20. Design a supplement that would earn a ✅ from this book. Name the six features.

Answer **1. A specific named deficiency or elevated requirement** — a population defined by a *measurable state*, not an aspiration. Not "adults who want more energy." **2. A mechanism that specifies why this group and not everyone** — B12 isn't in plants; metformin blocks absorption. **The mechanism names the gap.** **3. A measurable status marker** — ferritin, 25(OH)D, serum B12. *(This is what magnesium lacks, and why its verdict is 🟡 despite a plausible case.)* **4. A hard outcome, not a marker** — neural tube defects, not homocysteine. Chapter 13's graveyard is full of supplements that moved the marker beautifully. **5. A dose matching the tested dose, disclosed on the label.** **6. A trial in the deficient population**, not in replete volunteers. **And the second route:** creatine and caffeine correct nothing. They earned their verdicts through **hundreds of trials, in the relevant population, on outcomes people care about, at disclosed doses.** Two routes to a ✅ — fix a real gap, or accumulate overwhelming evidence. **Almost nothing on the shelf attempts either.**

Applied Scenario

21. A 61-year-old man is brought to the emergency department with chest pain. He has type 2 diabetes, takes metformin, atorvastatin and lisinopril, and his daughter mentions he "takes a lot of vitamins." His troponin is low and his ECG is non-diagnostic.

What do you want to know, and what could go wrong?

Answer **This is Walt, and the answer is one question: ⚠️ *what exactly is he taking, and can someone bring the bottles or a list?*** **What could go wrong — the specific failure mode:** **⚠️ Biotin interference.** If he takes any product containing high-dose biotin — "hair, skin and nails," an "immune" blend, a B-complex — the **troponin may be falsely low** in a sandwich-format assay. That is the dangerous direction, because it produces false reassurance and discharge. **The FDA has documented a reported death from exactly this.** The action is to repeat on a different platform, or to interpret the result knowing the interference exists. **What else I'd want from the list:** - ⚠️ **Zinc dose** — above ~40 mg sustained risks copper deficiency (Ch 14) - ⚠️ **Anything glucose-lowering** stacked on metformin, especially **berberine** — unmonitored hypoglycaemia risk - ⚠️ **Fish oil, ginkgo, garlic, vitamin E** — bleeding risk, relevant if he's heading for catheterization or anticoagulation - ⚠️ **St John's Wort** — CYP3A4 induction affecting statin and other drug levels - **Creatine** — if present, expect raised creatinine that is an artefact, not renal impairment - **B12** — given nine-plus years of metformin, worth checking regardless of why he's here (Ch 13) **And the systemic point:** none of this is exotic knowledge. It requires someone to **ask, and to read a label.** Walt's outcome depended on a junior doctor doing that at half past four in the morning. **Which is why this book has asked three times for a list in your phone** — because the situation where it matters most is the one where you may not be able to tell anyone anything.

Scoring

Score Reading
18–21 Strong. Part III is done — and you can now read a supplement shelf better than most clinicians.
14–17 Good. Reread §16.1 (DSHEA) and §16.9 (the framework).
10–13 Reread §16.1, §16.3 and §16.5 — the regulation, what works, and what's dangerous.
Under 10 Reread the chapter. Then do Exercise C1 anyway — the cupboard teaches more than the text.

And whatever you scored: write the list. Four minutes. It's been asked for in Chapters 13, 14 and 16, and this is the last time.