Know what to take, and for how long.

Absorption and timingSplit calcium into doses of 500 mg or less; absorption caps out above that.Testing and disclosureTell your pharmacist everything you take, including the things that feel too harmless to mention.Tier shiftsCalcium and vitamin D become ongoing after menopause or with osteoporosis treatment.Where the harm isSt John's wort can make hormonal contraception fail. This is not theoretical.Where the money goesMagnesium oxide is cheap because it is poorly absorbed — mostly a laxative.Absorption and timingIron, calcium, zinc and magnesium compete for absorption — space them two hours apart.Testing and disclosureSeveral supplements need stopping one to two weeks before surgery — ask your surgeon.Tier shiftsIron becomes ongoing with chronic blood loss, malabsorption, or after bariatric surgery.Where the harm isStacking is the most common way people exceed limits — a multivitamin plus a single nutrient plus fortified food.Where the money goesBCAAs are largely redundant if your total protein intake is already adequate.Absorption and timingTake iron with vitamin C, and away from tea, coffee and dairy.Testing and disclosureBiotin distorts thyroid and troponin lab results. Stop it two days before blood tests.Tier shiftsFolate is Tier 2 generally, Tier 1 during pregnancy planning and the first trimester.Where the harm isRed yeast rice is a statin by another name, with every statin risk attached.Where the money goes“Proprietary blend” on a label means you cannot know the doses you are paying for.Absorption and timingMelatonin works on timing, not dose — take it two to three hours before target bedtime.Testing and disclosureSaw palmetto lowers PSA and can mask prostate cancer screening.Tier shiftsB12 moves to Tier 1 for vegans, over-60s, and anyone on metformin or long-term acid blockers.Where the harm isConcentrated green tea extract has caused acute liver failure. Brewed tea has not.Where the money goesPrice per gram varies enormously between brands for chemically identical compounds.Absorption and timingTake fat-soluble vitamins and omega-3 with a meal containing fat.Testing and disclosureFolate supplements can hide B12 deficiency while nerve damage continues underneath.Tier shiftsA Tier 3 herb taken indefinitely with no condition to treat has quietly become a Tier 4 habit.Where the harm isExcess iron is stored, not excreted. Never supplement it without a ferritin test.Where the money goesCollagen powder is largely a glycine delivery system at several times the price.Absorption and timingPsyllium slows absorption of everything; separate it from all medication by two hours.Testing and disclosureCreatine raises measured creatinine without indicating kidney damage. Tell your doctor.Tier shiftsCreatine sits in Tier 4 for most people, but behaves like Tier 2 for vegetarians with genuinely lower baseline stores.Where the harm isProlonged high-dose B6 causes peripheral neuropathy that can persist after stopping.Where the money goesRead the active amount on the back, not the total capsule weight on the front.Absorption and timingZinc on an empty stomach commonly causes nausea. Take it with food.Where the harm isPowdered caffeine has killed people through measurement error. Never eyeball the dose.Where the money goesGreens powders cannot replace vegetables; fibre and volume don't survive the process.Where the harm isFat-soluble vitamins A, D, E and K accumulate. This is where more is genuinely worse.Absorption and timingSplit calcium into doses of 500 mg or less; absorption caps out above that.Testing and disclosureTell your pharmacist everything you take, including the things that feel too harmless to mention.Tier shiftsCalcium and vitamin D become ongoing after menopause or with osteoporosis treatment.Where the harm isSt John's wort can make hormonal contraception fail. This is not theoretical.Where the money goesMagnesium oxide is cheap because it is poorly absorbed — mostly a laxative.Absorption and timingIron, calcium, zinc and magnesium compete for absorption — space them two hours apart.Testing and disclosureSeveral supplements need stopping one to two weeks before surgery — ask your surgeon.Tier shiftsIron becomes ongoing with chronic blood loss, malabsorption, or after bariatric surgery.Where the harm isStacking is the most common way people exceed limits — a multivitamin plus a single nutrient plus fortified food.Where the money goesBCAAs are largely redundant if your total protein intake is already adequate.Absorption and timingTake iron with vitamin C, and away from tea, coffee and dairy.Testing and disclosureBiotin distorts thyroid and troponin lab results. Stop it two days before blood tests.Tier shiftsFolate is Tier 2 generally, Tier 1 during pregnancy planning and the first trimester.Where the harm isRed yeast rice is a statin by another name, with every statin risk attached.Where the money goes“Proprietary blend” on a label means you cannot know the doses you are paying for.Absorption and timingMelatonin works on timing, not dose — take it two to three hours before target bedtime.Testing and disclosureSaw palmetto lowers PSA and can mask prostate cancer screening.Tier shiftsB12 moves to Tier 1 for vegans, over-60s, and anyone on metformin or long-term acid blockers.Where the harm isConcentrated green tea extract has caused acute liver failure. Brewed tea has not.Where the money goesPrice per gram varies enormously between brands for chemically identical compounds.Absorption and timingTake fat-soluble vitamins and omega-3 with a meal containing fat.Testing and disclosureFolate supplements can hide B12 deficiency while nerve damage continues underneath.Tier shiftsA Tier 3 herb taken indefinitely with no condition to treat has quietly become a Tier 4 habit.Where the harm isExcess iron is stored, not excreted. Never supplement it without a ferritin test.Where the money goesCollagen powder is largely a glycine delivery system at several times the price.Absorption and timingPsyllium slows absorption of everything; separate it from all medication by two hours.Testing and disclosureCreatine raises measured creatinine without indicating kidney damage. Tell your doctor.Tier shiftsCreatine sits in Tier 4 for most people, but behaves like Tier 2 for vegetarians with genuinely lower baseline stores.Where the harm isProlonged high-dose B6 causes peripheral neuropathy that can persist after stopping.Where the money goesRead the active amount on the back, not the total capsule weight on the front.Absorption and timingZinc on an empty stomach commonly causes nausea. Take it with food.Where the harm isPowdered caffeine has killed people through measurement error. Never eyeball the dose.Where the money goesGreens powders cannot replace vegetables; fibre and volume don't survive the process.Where the harm isFat-soluble vitamins A, D, E and K accumulate. This is where more is genuinely worse.