Swanson L-Carnitine
vs
21st Century Vitamin B-12 1000 mcg
Supplement Comparison

  • Calcium: Swanson L-Carnitine has 90% more
  • The image below shows:
    • Side-by-side charts with label nutrient amounts, per serving
    • Nutrient forms as listed on the label
    • 5 nutrients compared
Bar chart: per-serving label amounts and listed forms for Swanson L-Carnitine vs 21st Century Vitamin B-12 1000 mcg.

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Frequently asked questions

Which active ingredients does Swanson L-Carnitine have?

  • Calcium
  • L-Carnitine

Which active ingredients does 21st Century Vitamin B-12 1000 mcg have?

  • Vitamin B12 (Cobalamin) appears as Cyanocobalamin
  • Calcium appears as Calcium Carbonate

Which categories do Swanson L-Carnitine and 21st Century Vitamin B-12 1000 mcg belong to?

  • Amino Acid Formula
  • Single Vitamin

What health concerns do Swanson L-Carnitine and 21st Century Vitamin B-12 1000 mcg address?

  • Athletic Performance
  • Muscle Support
  • Energy & Metabolism
  • Recovery & Repair
  • General Health

Which product has a higher amount of Calcium per serving?

  • Swanson L-Carnitine has the highest total amount of Calcium: 190 mg per serving

How do the serving sizes compare between the two supplements?

  • Serving size:
    • Swanson L-Carnitine: 1 tablet
    • 21st Century Vitamin B-12 1000 mcg: 1 tablet
  • Calcium
    • This supplement has 190 mg
    • Recommended Dietary Allowance in men: 1000 mg
    • Recommended Dietary Allowance in women: 1000 mg
    • Tolerable Upper Intake Level: 2500 mg
  • Vitamin B12 (Cobalamin)
    • This supplement has 1000 mcg
    • Recommended Dietary Allowance in men: 2.4 mcg
    • Recommended Dietary Allowance in women: 2.4 mcg
    • Tolerable Upper Intake Level: Not established
  • Calcium
    • This supplement has 100 mg
    • Recommended Dietary Allowance in men: 1000 mg
    • Recommended Dietary Allowance in women: 1000 mg
    • Tolerable Upper Intake Level: 2500 mg

Last updated: February 4, 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.
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  • See an error? Report it through our Contact page.
  • Author: VIOscan Research Team