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Multivitamins
What Multivitamins is, what the NIH ODS fact sheet says the evidence supports, typical doses, timing, and the cautions that come with it.
Supplements are not medicines and this page is not medical advice. Doses that help one person can harm another — with medicines, kidney or liver conditions, pregnancy, or before surgery, talk to a clinician before starting anything. More is not better.
What it is
Combination products with no standard definition; contents vary product to product.
What the evidence supports
ODS: may fill nutrient gaps for people who eat poorly, but they are not a substitute for food and do not prevent chronic disease in well-nourished people.
Dose and timing
Follow the label; one product's dose says nothing about another's. With food, per the label.
Cautions
Check the label against your actual needs — the iron in a "men's" formula differs from a "pregnancy" one for a reason.
Interactions are the hidden risk: supplements can change how medicines work and vice versa. Give your clinician the full list before anything else.
Source: NIH Office of Dietary Supplements — Multivitamins fact sheet · checked 2026-09-03
Frequently asked questions
What does Multivitamins do?
Combination products with no standard definition; contents vary product to product.
Does Multivitamins work?
ODS: may fill nutrient gaps for people who eat poorly, but they are not a substitute for food and do not prevent chronic disease in well-nourished people.
How much multivitamins should I take?
Follow the label; one product's dose says nothing about another's. With food, per the label.
Is Multivitamins safe?
Check the label against your actual needs — the iron in a "men's" formula differs from a "pregnancy" one for a reason. And the standing rule: tell your clinician everything you take — supplements interact with medicines.
Creatine
Studied doses: 3-5 g per day; loading protocols use about 20 g/day in 4 doses for 5-7 days.
Magnesium
RDA: men 400-420 mg, women 310-320 mg per day.
Vitamin D
RDA: 600 IU (15 mcg) to age 70, then 800 IU (20 mcg). UL 4000 IU.
Omega-3s (EPA/DHA)
No RDA for EPA/DHA; ALA: men 1.6 g, women 1.1 g per day. Many products supply 250-500 mg combined EPA+DHA per day.
Melatonin
Studied doses commonly 0.5-5 mg, taken 30-60 minutes before bed.
Iron
RDA: men 8 mg, women 19-50 18 mg, pregnancy 27 mg per day.
Log it, and show it to your doctor
TempoLife keeps supplements, food and sleep in one place — a list your clinician can actually review.