Chapter 16 — Key Takeaways
One page. Closes Part III.
DSHEA 1994 — the fact that explains everything else
| Drugs | Supplements | |
|---|---|---|
| Pre-market approval | Required (safety and efficacy) | None |
| Burden of proof | Manufacturer proves it works | FDA must prove harm — after marketing |
| Claims | Disease claims, if proven | Structure/function: supports, promotes, helps maintain |
| Disclaimer | — | "This statement has not been evaluated by the FDA." |
The drug pipeline has gates throughout; the supplement pipeline has one, at the end. The burden of proof runs backwards.
"Supports immune health" is not fluff obscuring a claim. It IS the claim — and it's the strongest thing the product is permitted to say. A product that could say "reduces the risk of X" would.
⚠️ Consequence: "if it were dangerous it wouldn't be sold" is precisely inverted. The safety data is generated by consumers.
What's In the Bottle
Under- and over-dosing · substitution and absent botanicals · ⚠️ adulteration with undeclared pharmaceuticals — recurring in weight loss (sibutramine), sexual enhancement (sildenafil analogues), bodybuilding (anabolic steroids).
Third-party certification — NSF Certified for Sport, Informed Sport, USP Verified, ConsumerLab — verifies contents, not efficacy. ⚠️ Non-negotiable for tested athletes; strict liability applies.
✅🟢 The Short List That Works
| Verdict | Ch | |
|---|---|---|
| Folic acid, preconception | ✅ | 13 |
| B12 — vegans, malabsorption, metformin | ✅ | 13 |
| Vitamin D in the deficient | ✅ | 13 |
| Iron in the iron-deficient (⚠️ test first) | ✅ | 14 |
| Iodine in pregnancy | ✅ | 14 |
| ORS in diarrhoeal illness | ✅ | 15 |
| Creatine monohydrate — strength, power, lean mass | ✅ | 16 |
| Caffeine — exercise performance | 🟢 | 16 |
| Psyllium — LDL, glycemia, stool | 🟢 | 11 |
| Electrolytes in prolonged exercise/heat | 🟢 | 15 |
| Omega-3 without fish | 🟡 | 9 |
| Protein powder as convenience | 🟡 | 8 |
Every nutritional ✅ corrects a measured deficiency or meets an elevated requirement in a defined group. None improves a replete person. Creatine and caffeine are the deliberate exceptions — ergogenic, not nutritional.
Creatine, specifically
Mechanism: creatine phosphate regenerates ATP instantly — the fastest energy system, a buffer not a fuel. Supplementation enlarges the battery. Protocol: monohydrate, 3–5 g/day, consistently, no loading required, third-party certified. Cost: $0.10–$0.20/day. ⚠️ Skip "advanced," "buffered," "liposomal" — more expensive, no advantage. ⚠️ Raises serum creatinine — an artefact, not kidney injury. Tell your clinician. And it does essentially nothing for endurance, because that's not the limiting system.
❌ The Long List
Multivitamins in the well-nourished 🟠 · high-dose antioxidants ❌ · vitamin C for colds ❌ · calcium supplements in healthy adults 🟠 · fat-loss and "metabolism" products ❌ · L-carnitine and exogenous ketones ❌ · detox and cleanse ❌ · colloidal minerals 🟠 · testosterone boosters ❌ · proprietary blends ❌ · most nootropics ⚗️ · collagen 🟡 · glucosamine 🟡.
⚠️ The Dangerous List
Biotin (assay interference) · zinc >40 mg (copper deficiency) · preformed vitamin A in pregnancy (teratogenic) · B6 (neuropathy) · iron without testing (overload; hemochromatosis; child poisoning) · green tea extract, garcinia, kava (hepatotoxicity — NIH LiverTox) · ephedra/synephrine (cardiovascular) · kelp (thyroid) · yohimbine · adulterated products.
⚠️ Interactions — St John's Wort is the most dangerous common one: a potent CYP3A4 inducer reducing levels of oral contraceptives (contraceptive failure), warfarin, immunosuppressants (transplant rejection), antiretrovirals. Plus bleeding risk (fish oil, ginkgo, garlic, vitamin E), berberine on diabetes drugs, mineral–thyroid timing, potassium with ACE inhibitors/ARBs.
⚠️ Interference — harm to the measurement
| Biotin | Biotin–streptavidin immunoassays. Sandwich format → falsely LOW (troponin, TSH, hCG). Competitive → falsely high. FDA safety communications 2017/2019, including a reported death. |
| Creatine | Raises creatinine — artefact |
| Vitamin C | Some glucose meters, urine dipsticks |
| Iron | Distorts iron studies if recently dosed |
⚠️ Stop biotin several days before planned blood tests and tell the clinician. Check "hair, skin and nails," "immune" blends, and B-complexes.
Reading a Label
Supplement Facts panel → compare to the UL, not the RDA · ❌ proprietary blend = unassessable = unsupported · other ingredients · certification marks · read the claim's verb · believe the disclaimer.
| Phrase | Means |
|---|---|
| "Clinically studied" | A study exists involving the ingredient. Not this product, dose, combination, or outcome. |
| ⚠️ "Pharmaceutical grade" | Nothing — no legal definition |
| "Doctor formulated" | A doctor was involved. Chapter 1 §1.5 applies to doctors too. |
| "Natural" | An origin claim, not a safety one |
| "Advanced / buffered / liposomal" | Usually a premium form with no demonstrated advantage |
The Six Questions (§16.9)
- Disease claim or structure/function claim?
- Evidence, at what rung?
- Is the dose in the product the dose in the studies?
- Tested in people like me — deficient or replete?
- Harm profile — interactions, UL, hepatotoxicity, assay interference
- Annual cost, and the alternative
Plus Chapter 1's: what happens to the seller's income if you decline?
Verdict Summary
| Claim | Verdict |
|---|---|
| Creatine monohydrate improves strength, power, lean mass | ✅ Well supported |
| Caffeine improves exercise performance | 🟢 Probably true |
| Proprietary blends deliver clinically-studied ingredients | ❌ Not supported — unassessable by design |
| "It's natural, so it's safe" | 🟠 Probably false — origin ≠ safety; concentration is the mechanism |
Walt's Cabinet, Closed
$2,244/year → $310. Stopped: multivitamin (it masked his B12 deficiency), curcumin, "liver detox," vitamin E, and the immune blend (biotin 3,000 µg + zinc 50 mg). Kept: vitamin D reduced to 2,000 IU, magnesium, fish oil. ⚠️ Berberine referred to his GP rather than stopped unilaterally.
Added: targeted B12 (~$18/yr) and a fiber ramp 14 → 30 g (~$80/yr). At five months: A1c 7.4% → 6.9%.
The Economics
Creatine $40–70/yr · folic acid $11 · B12 $18 · vitamin D $15 · ORS $8 · fiber gap $80 — versus — Walt's cabinet $2,244 · metabolism aisle $2,880 · protein bars $1,060 · daily electrolytes $220–730 · a pre-workout $584.
Everything with strong evidence is in the top group. The US market is estimated well over $50 billion — which is not a measure of nutritional need.
One Thing to Remember
Walt's troponin came back low, and it was wrong.
Supplements are not "can't hurt." They can make your medical care worse without doing anything to your body at all — and you cannot be careful about a risk you have no category for.
⚠️ Write the list. Four minutes. Phone and wallet. Tell someone it exists.