Vitamin D2 vs D3: What to Compare on the Label

Compare D2 and D3 listings by the exact form, IU or micrograms, serving size, and package quantity without treating the label as personal advice.

Vitamin D labels commonly name vitamin D2 (ergocalciferol) or vitamin D3 (cholecalciferol). A fair catalog comparison records the form and amount exactly as printed instead of treating a higher front-label number as an overall ranking.

Compare the amount and unit

Vitamin D may be listed in micrograms (mcg) and/or international units (IU). For vitamin D, 1 mcg equals 40 IU. Keep the original unit and, if useful, show the converted amount beside it so the source value remains traceable. Do not compare numbers until their units match.

Calculate value from the labeled serving

Record the amount per serving, the serving definition, and servings per container. If comparing price per 1,000 IU, use package price ÷ total labeled IU × 1,000. This is a reporting unit, not a recommended intake. Keep D2 and D3 identified in the result, and leave the normalized price blank if the label or serving count is incomplete.

Frequently asked questions

Are D2 and D3 the same ingredient?

No. They are two forms of vitamin D. Copy the exact form name from the product label.

Can I compare IU directly with mcg?

Convert to a common unit first; 1 mcg of vitamin D equals 40 IU.

Sources and review

Sources: NIH Office of Dietary Supplements, vitamin D fact sheet; FDA, Daily Value and label information. Reviewed September 28, 2026.

Use current SuppScan data

SuppScan presents the product data available in its catalog and does not manufacture missing values. Open the Vitamin D comparison to review current offers and normalized metrics.