IU Converter
Convert International Units (IU) to mg or mcg with laboratory-grade accuracy. Based on WHO/NIH 2026 standards.
Select a Substance
Vitamin D3
Vitamin D3 is crucial for bone health, immune function, and calcium absorption. 1 IU = 0.025 mcg.
1 IU = 0.025 mcg
Vitamin A Retinol
Preformed Vitamin A from animal sources. Essential for vision, immune function, and reproduction.
1 IU = 0.3 mcg RAE
Vitamin A Beta-Carotene
Provitamin A from plant sources. Converted to retinol in the body as needed.
1 IU = 0.05 mcg RAE
Vitamin E Natural
Natural RRR-alpha-tocopherol. More bioavailable than synthetic forms.
1 IU = 0.67 mg
Vitamin E Synthetic
Synthetic all-rac-alpha-tocopherol. Less bioavailable than natural form.
1 IU = 0.45 mg
Insulin
Standard human insulin. Dosage must be determined by a healthcare provider.
1 IU = 0.0347 mg