Vitamin A is available in a variety of forms, including retinol, retinyl acetate and retinyl palmitate. Vitamin A is measured in both international units — commonly abbreviated IU — and micrograms. Vitamin A is a fat-soluble vitamin, making overdose more likely than with water-soluble vitamins. Therefore, knowing how to convert a measurement of retinyl palmitate from IU to micrograms can be beneficial when determining the dosage of a vitamin supplement.
Locate the amount of vitamin A palmitate on the nutrition facts table.
Multiply the amount of vitamin A palmitate in IU by 0.55 to determine the amount in micrograms. For example, 100 IU of vitamin A palmitate is equivalent to 55 mcg.
Check your work by dividing the amount of vitamin A palmitate micrograms by its equivalent amount in IU. The quotient will be 0.55 if you correctly converted IU to micrograms. For example, if you determined that 200 IU of vitamin A palmitate is equivalent to 110 mcg, you would check your work by dividing 110 mcg by 200 IU. The quotient is 0.55, which means that 110 mcg of vitamin A palmitate is, in fact, equivalent to 200 IU of vitamin A palmitate.
- “Foundations of Nursing”; Lois White, Gena Duncan and Wendy Baumle; 2010
- "Basic Nutrition and Diet Therapy"; Staci Nix; 2005