Which unit is used to specify the vitamin D dose for breastfed infants in the first 2 months of life?

Which unit is used to specify the vitamin D dose for breastfed infants in the first 2 months of life?

• A. mg
• B. IU
• C. mcg
• D. g

Answer: (B)

Vitamin D dosing for breastfed infants in the early weeks is expressed in International Units because this unit reflects the vitamin’s biological activity rather than its weight. The potency of vitamins is standardized in IU, so dosing guidelines specify how much activity the infant receives. For vitamin D, 1 microgram equals 40 IU, so the typical recommended amount (about 400 IU per day) corresponds to roughly 10 micrograms, but the unit used in guidelines and labeling is IU. Mass units like milligrams, micrograms, and grams don’t capture the activity level in the same way, which is why IU is the standard for this purpose.

Vitamin D dosing for breastfed infants in the early weeks is expressed in International Units because this unit reflects the vitamin’s biological activity rather than its weight. The potency of vitamins is standardized in IU, so dosing guidelines specify how much activity the infant receives. For vitamin D, 1 microgram equals 40 IU, so the typical recommended amount (about 400 IU per day) corresponds to roughly 10 micrograms, but the unit used in guidelines and labeling is IU. Mass units like milligrams, micrograms, and grams don’t capture the activity level in the same way, which is why IU is the standard for this purpose.