Vitamin D2 vs D3 and mcg vs IU: Reading the Label

Compare vitamin D by D2 or D3 form, mcg and IU units, serving size, and whether calcium or K2 is included.

This page is for general reference only and is not medical advice, diagnosis, treatment, or prescription. Research and regulatory status can change, so ask a qualified professional when medical judgment is needed.

2026 search trend

Vitamin D searches often mix standalone D3 with calcium or K2 blends. Read the unit and actual serving amount before relying on the front-label number.

What to compare on product labels

• Identify vitamin D2 (ergocalciferol) or D3 (cholecalciferol).
• One mcg equals 40 IU, so convert labels to the same unit before comparing.
• For drops, check drop versus dropper; for tablets or gummies, check how many pieces make one serving.

Other names and search terms

Ingredients often compared together

Cautions

• Vitamin D is fat-soluble; total amounts across multiple products matter, especially with long-term high intake.
• Ask a clinician if you have kidney or calcium-related conditions or take medicines that may interact.

Check products on Supplecipe

Search the ingredient, switch to the single-ingredient filter, then open product comparison or stack analysis for the products you are considering.