Single nutrients and multivitamins, compared by form, dose per serving and how that dose sits against the RDA and upper limit. Start with the nutrients people most often run low on.
Start here: Iron for low ferritin · Best magnesium supplements · Calcium and vitamin D
We compared 20 magnesium complexes for women and 8 went over the 350 mg upper limit. See our 6 picks, with real magnesium per serving, forms and testing checked.
We compared 15 magnesium glycinate gummies by actual magnesium per serving, sugar and testing. See which labels add up and how much magnesium you really get.
We compared 16 multivitamins for men over 50 for B12, vitamin D, dyes and upper limits. See which are USP or NSF verified, which to skip, and why it matters.
Compare 6 iron and vitamin D supplements by the dose of each nutrient, form and additives, and learn when two separate pills work better than one combo.
Compare 6 iron supplements for life after gastric sleeve surgery by dose, form and tolerability, with ASMBS guidance on how much iron to take and when.
We compared 16 liposomal vitamin C supplements on real vitamin C per serving, form, other ingredients and cost. See which 9 made the cut and which labels overstate the dose.
We compared 16 iron and “ferritin” supplements on form, dose and purity. See the 7 best picks for low ferritin, the new 2026 ferritin cutoffs and how to dose.
We compared 17 vitamin C labels by dose, form, testing and cost. See the 7 best picks, why 500 mg often beats 1,000 mg, and who should skip high doses.
We compared 16 vitamin C supplements for kids on dose by age, sugar, testing and cost. See which 6 made the cut and how much vitamin C your child actually needs.
We compared 16 calcium and vitamin D labels on form, dose, purity and value. See the 7 best picks, RDA and upper limits, and who should skip supplements.
We compared 11 copper supplements on form, dose and purity. See the 6 best picks, who actually needs copper, how to balance it with zinc and the 10 mg upper limit.
We compared 14 boron supplements on form, dose and label accuracy. See the 6 best picks, how much boron to take, the 20 mg upper limit and what the evidence shows.
We compared 16 beef organ supplements by organs, amount per organ, sourcing and fillers. Our 7 picks include the best overall, value and men’s options.
We compared 18 magnesium labels by form, elemental dose and testing. See the best glycinate, citrate, L-threonate, taurate and malate picks, plus safe limits.
325 mg ferrous sulfate gives 65 mg of iron. We compared 13 iron products on testing, dyes and cost per tablet to find the best 325 mg options.
We compared 14 multivitamins with iron on iron dose and form, additives and testing. See which multi fits women, men and anyone who wants low-dose iron.
Most men don’t need extra iron. If a blood test shows yours is low, these 7 iron supplements are the best options by form, dose and value.
We compared 16 iron supplements for pregnancy on dose, iron form and testing. See our top picks, how much iron you need, and when a higher dose is needed.
We compared 15 iron supplements for women by dose for each life stage, iron form and vitamin C. Pink Stork is our top pick; see 6 more by need.
We compared 15 gentle iron supplements by form, dose and other ingredients. Solgar Gentle Iron is our top pick for iron without constipation; see 6 more.