What is the recommended dosage of vitamin D for children in the Northern Hemisphere?

The recommended dosage of vitamin D for children in the Northern Hemisphere is 600 international units per day for ages 4 years to 18 years, including pregnant and lactating females, according to MedlinePlus. From birth to age 12 months, 400 international units per day is a sufficient dosage.

Vitamin D aids the body in absorbing calcium and phosphorus, which play significant roles in building and maintaining bone strength, explains WebMD. When the body receives exposure to sunlight, it manufactures vitamin D. Factors such as limited exposure to sunlight, protective clothing and sunscreen can prevent children from producing enough vitamin D from the sun.