Evidence-Based Supplement Dosing
Supplement dosing is not one-size-fits-all. The optimal dose depends on your body weight, existing nutrient levels, health goals, and potential interactions with medications or other supplements. Under-dosing wastes money (no therapeutic effect), while over-dosing certain nutrients — particularly fat-soluble vitamins A, D, E, and K — can cause toxicity. Evidence-based dosing targets the range shown effective in clinical trials while staying below established upper limits.
Key Facts
- Fat-soluble vitamins (A, D, E, K) accumulate in body fat and CAN reach toxic levels
- Water-soluble vitamins (B, C) are excreted daily and rarely cause toxicity at normal doses
- Magnesium absorption decreases above 200mg per dose — split large doses across the day
- Vitamin D requires 2-3 months at consistent dosing to reach steady-state blood levels
- Taking iron with vitamin C increases absorption by 2-3x; taking it with calcium blocks absorption
- The effective dose in research often differs from the amount listed on supplement labels
Bioavailability: Why the Form of a Supplement Matters
Bioavailability — the fraction of a nutrient that reaches systemic circulation in active form — varies enormously between supplement forms. Magnesium oxide has only 4% bioavailability vs magnesium glycinate at 80%. Curcumin alone has <1% absorption but with piperine (BioPerine) it increases 2000%. Methylcobalamin (B12) is immediately usable vs cyanocobalamin which requires liver conversion. CoQ10 as ubiquinol is 2-6x better absorbed than ubiquinone. When calculating doses, the form matters as much as the amount — 500mg of a poorly absorbed form may deliver less active compound than 200mg of a highly bioavailable one.
