Nordic Naturals Ultimate Omega Xtra
vs
Douglas Laboratories Vitamin D 1000 IU
Supplement Comparison

  • Vitamin D: same total amount on both labels
  • The image below shows:
    • Side-by-side charts with label nutrient amounts, per serving
    • Nutrient forms as listed on the label
    • 7 nutrients compared
Bar chart: per-serving label amounts and listed forms for Nordic Naturals Ultimate Omega Xtra vs Douglas Laboratories Vitamin D 1000 IU.

Try the VIOscan dashboard demo for free

Build comparison charts in seconds – no signup or card needed

This is a free preview of the $9.99/month premium dashboard

Use the interactive demo with multivitamins samples

Try Free Demo

Frequently asked questions

Which active ingredients does Nordic Naturals Ultimate Omega Xtra have?

  • Vitamin D appears as Cholecalciferol (D3)
  • Eicosapentaenoic Acid (EPA) appears as Re-esterified Triglycerides (rTG)
  • Docosahexaenoic Acid (DHA) appears as Re-esterified Triglycerides (rTG)

Which active ingredients does Douglas Laboratories Vitamin D 1000 IU have?

  • Vitamin D appears as Cholecalciferol (D3)

Which categories do Nordic Naturals Ultimate Omega Xtra and Douglas Laboratories Vitamin D 1000 IU belong to?

  • Fish Oil and Omega-3
  • Single Vitamin

What health concerns do Nordic Naturals Ultimate Omega Xtra and Douglas Laboratories Vitamin D 1000 IU address?

  • Anti-Inflammatory Support
  • Brain, Focus & Cognitive Function
  • Eye Health
  • General Health
  • Heart & Cardiovascular Health
  • Joint & Bone Health
  • Mood Support
  • Immune System Support

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

  • Both products list the same total amount of Vitamin D per serving

How do the serving sizes compare between the two supplements?

  • Serving size:
    • Nordic Naturals Ultimate Omega Xtra: 2 tablets
    • Douglas Laboratories Vitamin D 1000 IU: 1 tablet
  • 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 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

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.
  • 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