In 1993, the European Scientific Committee for Food set population reference intakes (PRI) for vitamin D in micrograms (mcg) and international units (IU) (60):
| Age | Males: mcg/day (IU/day) | Females: mcg/day (IU/day) |
| 6–12 months | 10–25 (400–1,000 IU) | 10–25 (400–1,000 IU) |
| 1–3 years | 10 (400 IU) | 10 (400 IU) |
| 4–10 years | 0–10 (0–400 IU) | 0–10 (0–400 IU) |
| 11–17 years | 0–15 (0– 600 IU) | 0–15 (0–600 IU) |
| 18-64 years | 0– 10 (0–400 IU) | 0–10 (0–400 IU) |
| 65 years and older | 10 (400 IU) | 10 (400 IU) |
| Pregnant | - | 10 (400 IU) |
| Breast-feeding | - | 10 (400 IU) |
However, most European countries have their own recommendations for vitamin D intake, recognizing that there may be insufficient sun exposure in larger or smaller groups of the population. As the dietary vitamin D intake is not sufficient to reach the estimated value for adequate intake (in the absence of endogenous synthesis), guaranteeing a desired 25-hydroxyvitamin D serum concentration of at least 50 nmol/l, the nutrition societies of Germany, Austria and Switzerland raised the recommended intake level for babies (0-11 months) to 10 mcg/day and for children and adults to 20 mcg/day in 2012.
In 2010, the U.S. Institute of Medicine established recommended dietary allowance (RDA) values for vitamin D, based on the prevention of deficiency (96):
| Life Stage | Age | Males: (mcg/day) (IU/day) | Females: (mg/day) (IU/day) |
| Infants | 0–6 months | 10 (400 IU) | 10 (400 IU) |
| Infants | 7–12 months | 10 (400 IU) | 10 (400 IU) |
| Children | 1–3 years | 15 (600 IU) | 15 (600 IU) |
| Children | 4–8 years | 15 (600 IU) | 15 (600 IU) |
| Children | 9–13 years | 15 (600 IU) | 15 (600 IU) |
| Adolescents | 14–18 years | 15 (600 IU) | 15 (600 IU) |
| Adults | 19-70 years | 15 (600 IU) | 15 (600 IU) |
| Adults | 71 years and older | 20 (800 IU) | 20 (800 IU) |
| Pregnancy | all ages | - | 15 (600 IU) |
| Breast-feeding | all ages | - | 15 (600 IU) |
Many experts believe that the AI levels should be increased (62, 63, 64, 94). They have proposed an optimal 25(OH)D blood plasma level above 30 nanograms/milliliter (75 nanomoles/liter). To achieve this level a vitamin D intake of at least 800–1,000 IU/day (20–25 micrograms) is required by adults and the elderly as shown by supplementation studies.
Furthermore, the American Academy of Pediatrics recently increased their vitamin D intake recommendation to 400 IU/day for all infants, children, and adolescents (65).
For a detailed overview of recommended daily intakes (PRIs/RDAs) of vitamins and minerals for adults derived from different countries and organizations see PDF.