The daily average requirement for vitamin D-3 is 15 micrograms for males and females, ages 1 through 70 years old, according to the Office of Dietary Supplements, a division of the National Institute of Health. Vitamin D3 is important to many bone-related functions.
From birth to age 1, the daily average requirement for vitamin D-3 is 10 micrograms. After the age of 70, the daily average requirement for D-3 increases to 20 micrograms. Vitamin D-3 can be acquired from food sources, vitamin supplements and exposure to sunlight, which causes vitamin D synthesis in the skin. Excessive vitamin D-3 intake can cause vitamin toxicity.