Recommended Supplement Doses

Vitamins and Minerals

Canadian Vitamins & Minerals – Quick Reference

RDA/AI and UL for healthy adults (general guidance). Use to fill gaps — not to replace a balanced diet.

Vitamins

Units: IU / µg / mg
UL = Upper Limit

Vitamin Main role(s) Adult RDA / AI (typical) UL Supplement notes
Vitamin D Bone health (Ca/P absorption), immune support 600 IU (15 µg) ages 19–70; 800 IU (20 µg) >70 4,000 IU/day (100 µg) Commonly low in Canada; take with a meal containing fat; track total intake from fortified foods.
Vitamin B12 Nerve function, red blood cells, DNA synthesis 2.4 µg None established Vegetarians/vegans & older adults often need supplements; consider sublingual or injections if absorption issues.
Folate (B9) Cell division, DNA synthesis 400 µg DFE 1,000 µg/day (synthetic folic acid) Anyone who could become pregnant: 400 µg folic acid daily. Monitor fortified foods.
Vitamin C Antioxidant; supports immune function; iron absorption 90 mg (men); 75 mg (women) 2,000 mg/day Smokers need +35 mg/day. High doses may cause GI upset.
Vitamin A Vision, immune function, cell differentiation 900 µg RAE (men); 700 µg RAE (women) 3,000 µg RAE/day Excess preformed vitamin A can be toxic. Beta-carotene is safer but not 1:1.
Vitamin E Antioxidant (cell membrane protection) 15 mg (α-tocopherol) 1,000 mg/day Use cautiously with anticoagulants; food sources often adequate.
Vitamin K Blood clotting; bone metabolism AI ~120 µg (men); 90 µg (women) Not established Keep intake consistent if on warfarin; consult clinician before changes.

Minerals

Units: µg / mg
UL = Upper Limit

Mineral Main role(s) Adult RDA / AI (typical) UL Supplement notes
Zinc Immune function, wound healing, taste/smell, DNA synthesis 11 mg (men); 8 mg (women) 40 mg/day Long-term >40 mg can cause copper deficiency. Vegetarians absorb less; avoid zinc nasal sprays.
Iron Oxygen transport (hemoglobin/myoglobin) 8 mg (men); 18 mg (women 19–50) 45 mg/day Supplement only if needed; excess is harmful. Take away from calcium, coffee/tea.
Magnesium Muscle/nerve function, bone, energy metabolism ~400–420 mg (men); 310–320 mg (women) 350 mg/day (supplemental only) Citrate/glycinate are gentler; may aid sleep/muscle tension. Mind GI tolerance.
Calcium Bone/teeth, muscle contraction, nerve signaling 1,000 mg (19–50); 1,200 mg (>50) 2,500 mg/day Absorption best ≤500 mg per dose; pair with vitamin D. Track diet+supplement total.
Selenium Thyroid hormone metabolism; antioxidant systems 55 µg 400 µg/day Brazil nuts are potent—easy to overshoot. Avoid chronic high dosing.
Iodine Thyroid hormone (T3/T4) synthesis 150 µg 1,100 µg/day Ensure iodized salt if avoiding processed foods/seafood; both low and high intake impair thyroid.

Notes: Values reflect typical Canadian DRIs for healthy adults (RDA or AI). UL applies to total intake unless noted (magnesium UL applies to supplements only).

Needs vary by age, sex, pregnancy/lactation, health status, and medications.

Sources: Health Canada Dietary Reference Intakes (vitamins & elements), Canada’s Food Guide; National Academies harmonized DRIs. Consult a clinician before starting or combining supplements.