Optimum Nutrition OPTI-MEN
vs
21st Century One Daily Women's
Supplement Comparison

  • Vitamin D: 21st Century One Daily Women's has 2.5× more
  • Magnesium: 21st Century One Daily Women's has 2.8× more
  • Vitamin C: 21st Century One Daily Women's has 50% more
  • The image below shows:
    • Side-by-side charts with label nutrient amounts, per serving
    • Nutrient forms as listed on the label
    • 59 nutrients compared
Bar chart: per-serving label amounts and listed forms for Optimum Nutrition OPTI-MEN vs 21st Century One Daily Women's.

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Frequently asked questions

Which active ingredients does Optimum Nutrition OPTI-MEN have?

  • Vitamin A
  • Vitamin C
  • Vitamin D
  • Vitamin E
  • Vitamin K
  • Vitamin B1 (Thiamin)
  • Vitamin B2 (Riboflavin)
  • Vitamin B3 (Niacin)
  • Vitamin B6 (Pyridoxine)
  • Vitamin B9 (Folate)
  • Vitamin B12 (Cobalamin)
  • Vitamin B7 (Biotin)
  • Vitamin B5 (Pantothenic Acid)
  • Alpha-Carotene
  • PABA
  • Calcium
  • Iodine
  • Magnesium
  • Zinc
  • Selenium appears as L-Selenomethionine
  • Chromium appears as Chromium nicotinate glycinate chelate
  • Molybdenum appears as Molybdenum A.A. chelate
  • Boron appears as Boron citrate
  • Vanadium appears as Vanadium citrate
  • Lutein
  • Lycopene
  • Inositol
  • Alpha Lipoic Acid
  • Zeaxanthin
  • Amino Men Blend by Optimum Nutrition
  • Phyto Men Blend by Optimum Nutrition
  • Viri Men Blend by Optimum Nutrition
  • Enzyme Blend by Optimum Nutrition
  • Cryptoxanthin

Which active ingredients does 21st Century One Daily Women's have?

  • Vitamin A appears as Retinyl Acetate
  • Vitamin C appears as Ascorbic Acid
  • Vitamin D appears as Cholecalciferol (D3)
  • Vitamin E appears as dl-Alpha Tocopheryl Acetate
  • Vitamin B1 (Thiamin) appears as Thiamin Mononitrate
  • Vitamin B2 (Riboflavin) appears as Riboflavin
  • Vitamin B3 (Niacin) appears as Niacinamide
  • Vitamin B6 (Pyridoxine) appears as Pyridoxine HCl
  • Vitamin B9 (Folate) appears as Folic Acid
  • Vitamin B12 (Cobalamin) appears as Cyanocobalamin
  • Vitamin B7 (Biotin) appears as D-Biotin
  • Vitamin B5 (Pantothenic Acid) appears as D-Calcium Pantothenate
  • Calcium appears as Calcium Carbonate
  • Iron appears as Ferrous Fumarate
  • Iodine appears as Potassium Iodide
  • Magnesium appears as Magnesium Oxide
  • Zinc appears as Zinc Oxide
  • Selenium appears as Sodium Selenate
  • Copper appears as Copper Sulfate

Which categories do Optimum Nutrition OPTI-MEN and 21st Century One Daily Women's belong to?

  • Multivitamin

What health concerns do Optimum Nutrition OPTI-MEN and 21st Century One Daily Women's address?

  • General Health
  • Men's Health
  • Women's Health

Which product has a higher amount of Vitamin D per serving?

  • 21st Century One Daily Women's has the highest total amount of Vitamin D: 1000 IU per serving

Which product has a higher amount of Magnesium per serving?

  • 21st Century One Daily Women's has the highest total amount of Magnesium: 42 mg per serving

Which product has a higher amount of Vitamin C per serving?

  • 21st Century One Daily Women's has the highest total amount of Vitamin C: 90 mg per serving

Which product has a higher amount of Zinc per serving?

  • 21st Century One Daily Women's has the highest total amount of Zinc: 8 mg per serving

Which product has a higher amount of Calcium per serving?

  • 21st Century One Daily Women's has the highest total amount of Calcium: 130 mg per serving

Which product has a higher amount of Vitamin B12 (Cobalamin) per serving?

  • Optimum Nutrition OPTI-MEN has the highest total amount of Vitamin B12 (Cobalamin): 25 mcg per serving

Which product has a higher amount of Vitamin B9 (Folate) per serving?

  • 21st Century One Daily Women's has the highest total amount of Vitamin B9 (Folate): 665 mcg DFE per serving

How do the serving sizes compare between the two supplements?

  • Serving size:
    • Optimum Nutrition OPTI-MEN: 3 tablets
    • 21st Century One Daily Women's: 1 tablet
  • Vitamin A
    • This supplement has 1500 mcg RAE
    • Recommended Dietary Allowance in men: 900 mcg RAE
    • Recommended Dietary Allowance in women: 700 mcg RAE
    • Tolerable Upper Intake Level: 3000 mcg RAE
  • Vitamin C
    • This supplement has 60 mg
    • Recommended Dietary Allowance in men: 90 mg
    • Recommended Dietary Allowance in women: 75 mg
    • Tolerable Upper Intake Level: 2000 mg
  • Vitamin D
    • This supplement has 400 IU
    • Recommended Dietary Allowance in men: 600 IU
    • Recommended Dietary Allowance in women: 600 IU
    • Tolerable Upper Intake Level: 4000 IU
  • Vitamin E
    • This supplement has 100 mg
    • Recommended Dietary Allowance in men: 15 mg
    • Recommended Dietary Allowance in women: 15 mg
    • Tolerable Upper Intake Level: 1000 mg
  • Vitamin K
    • This supplement has 75 mcg
    • Adequate Intake in men: 120 mcg
    • Adequate Intake in women: 90 mcg
    • Tolerable Upper Intake Level: Not established
  • Vitamin B1 (Thiamin)
    • This supplement has 1.5 mg
    • Recommended Dietary Allowance in men: 1.2 mg
    • Recommended Dietary Allowance in women: 1.1 mg
    • Tolerable Upper Intake Level: Not established
  • Vitamin A
    • This supplement has 700 mcg RAE
    • Recommended Dietary Allowance in men: 900 mcg RAE
    • Recommended Dietary Allowance in women: 700 mcg RAE
    • Tolerable Upper Intake Level: 3000 mcg RAE
  • Vitamin C
    • This supplement has 90 mg
    • Recommended Dietary Allowance in men: 90 mg
    • Recommended Dietary Allowance in women: 75 mg
    • Tolerable Upper Intake Level: 2000 mg
  • Vitamin D
    • This supplement has 1000 IU
    • Recommended Dietary Allowance in men: 600 IU
    • Recommended Dietary Allowance in women: 600 IU
    • Tolerable Upper Intake Level: 4000 IU
  • Vitamin E
    • This supplement has 15 mg
    • Recommended Dietary Allowance in men: 15 mg
    • Recommended Dietary Allowance in women: 15 mg
    • Tolerable Upper Intake Level: 1000 mg
  • Vitamin B1 (Thiamin)
    • This supplement has 2.4 mg
    • Recommended Dietary Allowance in men: 1.2 mg
    • Recommended Dietary Allowance in women: 1.1 mg
    • Tolerable Upper Intake Level: Not established
  • Vitamin B2 (Riboflavin)
    • This supplement has 1.95 mg
    • Recommended Dietary Allowance in men: 1.3 mg
    • Recommended Dietary Allowance in women: 1.1 mg
    • Tolerable Upper Intake Level: Not established

Last updated: February 18, 2026

  • Sources & Methodology: Nutrient data and forms are taken directly from Supplement Facts labels. Reviewed and standardized by the VIOscan Research Team. Learn more on the Methodology page.
  • We show the Recommended Dietary Allowance (RDA) when available. If no RDA exists, we show the Adequate Intake (AI). Tolerable Upper Intake Levels (UL) are used for upper limits. Unless otherwise noted, RDAs shown correspond to healthy adults aged 19–50 years and are sex-specific. Separate values exist for 51–70 years and >70 years, and pregnancy and lactation are excluded. All values come from the Dietary Reference Intakes (DRIs) published by the National Academies of Sciences, Engineering, and Medicine (NASEM), Food and Nutrition Board (FNB).
  • Transparency: We’re funded by our users. We don’t have sponsors or affiliate links, and we don’t sell supplements.
  • Editorial standards: we provide independent, impartial and objective data analysis.
  • This analysis is for educational purposes only. It is not a substitute for medical advice.
  • Questions? Read our Frequently Asked Questions or contact us, we’re here to help.
  • See an error? Report it through our Contact page.
  • Author: VIOscan Research Team