Vitamin D on a label: how to convert IU to mcg
One package says 1,000 IU and another says 25 mcg. For vitamin D those figures describe the same amount, provided both refer to the same serving.
Divide IU by 40
One microgram of vitamin D equals 40 IU. Divide 1,000 by 40 to get 25 mcg. To go the other way, multiply: 10 mcg equals 400 IU. Use this conversion specifically for vitamin D.
Check what counts as a serving
Suppose one label lists 25 mcg per two capsules. Each capsule contains 12.5 mcg. A second label lists 25 mcg per single capsule. The headline numbers match, but the amounts per capsule differ.
Keep the unit in your comparison
Write the product name, capsules per serving and micrograms per serving on one line. If more than one product in your cupboard contains vitamin D, those notes give a pharmacist a clearer starting point for a conversation about your own intake.
Product details · Together Health · NIH Office of Dietary Supplements
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