In a healthy person, the amount of vitamin D they need each day depends on their age.

Below are general guidelines for recommended daily amounts (RDA) of vitamin D for each age range.
Your needs will increase over time as your body ages and is less able to make and use the vitamin, doctor may recommend higher values if you are deficient in vitamin D or at risk, especially if you suffer from osteoporosis or other bone diseases. It is important to speak to your doctor about your individual needs.
- Infants 0-6 months need 400 IU daily (no more than 1,000 IU a day)
- Infants 6-12 months need 400 IU daily (no more than 1,500 IU a day)
- Children 1-3 years old need 600 IU daily (no more than 2,500 IU a day)
- Children 4-8 years old need 600 IU daily (no more than 3,000 IU a day)
- Over 9 years old need 600 IU daily (no more than 4,000 IU a day)
- Over 70 years old need 800 IU daily (no more than 4,000 IU a day)
- Pregnant/Lactating women (14-50) need 600 IU daily (no more than 4,000 IU a day)
Be aware of the upper limits on these amounts of vitamin D. Since vitamin D is fat-soluble, it can build up in your body to toxic levels. This can cause some pretty serious side effects. Therefore, do not exceed the recommended daily dose without your doctor’s suggestion.