21st Century Vitamin B-12 5000 mcg
vs
Douglas Laboratories Relora-Plex
Supplement Comparison

  • Vitamin B12 (Cobalamin): 21st Century Vitamin B-12 5000 mcg has 50× more
  • The image below shows:
    • Side-by-side charts with label nutrient amounts, per serving
    • Nutrient forms as listed on the label
    • 12 nutrients compared
Bar chart: per-serving label amounts and listed forms for 21st Century Vitamin B-12 5000 mcg vs Douglas Laboratories Relora-Plex.

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Frequently asked questions

Which active ingredients does 21st Century Vitamin B-12 5000 mcg have?

  • Vitamin B12 (Cobalamin) appears as Cyanocobalamin

Which active ingredients does Douglas Laboratories Relora-Plex have?

  • 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
  • Relora Blend

Which categories do 21st Century Vitamin B-12 5000 mcg and Douglas Laboratories Relora-Plex belong to?

  • Single Vitamin
  • B-Complex Formula
  • Herbal Extract

What health concerns do 21st Century Vitamin B-12 5000 mcg and Douglas Laboratories Relora-Plex address?

  • General Health
  • Mood Support
  • Stress Management
  • Weight Management

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

  • 21st Century Vitamin B-12 5000 mcg has the highest total amount of Vitamin B12 (Cobalamin): 5000 mcg per serving

How do the serving sizes compare between the two supplements?

  • Serving size:
    • 21st Century Vitamin B-12 5000 mcg: 1 tablet
    • Douglas Laboratories Relora-Plex: 2 capsules
  • Vitamin B12 (Cobalamin)
    • This supplement has 5000 mcg
    • Recommended Dietary Allowance in men: 2.4 mcg
    • Recommended Dietary Allowance in women: 2.4 mcg
    • Tolerable Upper Intake Level: Not established
  • Vitamin B1 (Thiamin)
    • This supplement has 10 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 10 mg
    • Recommended Dietary Allowance in men: 1.3 mg
    • Recommended Dietary Allowance in women: 1.1 mg
    • Tolerable Upper Intake Level: Not established
  • Vitamin B3 (Niacin)
    • This supplement has 10 mg
    • Recommended Dietary Allowance in men: 16 mg
    • Recommended Dietary Allowance in women: 14 mg
    • Tolerable Upper Intake Level: 35 mg
  • Vitamin B6 (Pyridoxine)
    • This supplement has 10 mg
    • Recommended Dietary Allowance in men: 1.3 mg
    • Recommended Dietary Allowance in women: 1.3 mg
    • Tolerable Upper Intake Level: 100 mg
  • Vitamin B9 (Folate)
    • This supplement has 333 mcg DFE
    • Recommended Dietary Allowance in men: 400 mcg DFE
    • Recommended Dietary Allowance in women: 400 mcg DFE
    • Tolerable Upper Intake Level: 1000 mcg DFE
  • Vitamin B12 (Cobalamin)
    • This supplement has 100 mcg
    • Recommended Dietary Allowance in men: 2.4 mcg
    • Recommended Dietary Allowance in women: 2.4 mcg
    • Tolerable Upper Intake Level: Not established

Last updated: February 5, 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).
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  • 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.
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  • Author: VIOscan Research Team