From the Guidelines
The recommended daily intake of vitamin D is 400-600 IU for children and adolescents, and 600-800 IU for adults, with specific recommendations varying by age and health status. According to the most recent and highest quality study, the ESPGHAN Committee on Nutrition recommends a total daily vitamin D intake of 400 IU/day for infants and 600 IU/day for children and adolescents 1. This is supported by other studies, including the American Academy of Pediatrics and the Institute of Medicine, which also recommend daily vitamin D intake of 400-600 IU for children and 600-800 IU for adults 1.
Key Considerations
- Vitamin D is essential for calcium absorption and bone health, immune function, and reducing inflammation.
- Foods rich in vitamin D include fatty fish, fortified milk, orange juice, cereals, and egg yolks.
- Some individuals may need higher doses if they have limited sun exposure, darker skin, or certain medical conditions.
- If supplementing, vitamin D3 (cholecalciferol) is generally preferred over vitamin D2 as it's more effective at raising blood levels.
- Taking vitamin D with a meal containing some fat improves absorption.
Special Populations
- Preterm infants on parenteral nutrition (PN) should receive 200-1000 IU/day of vitamin D, while term infants up to 12 months of age should receive 400 IU/day, and older children should receive 400-600 IU/day 1.
- Pediatric patients receiving long-term PN should be monitored periodically for vitamin D deficiency, and additional supplementation should be provided if necessary 1.
- Oral supplementation of vitamin D should be considered in patients on partial PN as well as during weaning from PN 1.
From the Research
Vitamin D Daily Requirement
The daily requirement for vitamin D is a topic of ongoing research and debate. Several studies have investigated the optimal dosage of vitamin D for adults in the general population.
- A daily vitamin D supplementation with 2000 international units (IU) (50 µg) of vitamin D3 may be considered a simple, effective, and safe dosage to prevent and treat vitamin D deficiency in the adult general population 2.
- This dose may improve some health outcomes and is sufficient to raise and maintain serum 25(OH)D concentrations above 50 nmol/L (20 ng/mL) and above 75 nmol/L (30 ng/mL) in >99% and >90% of the general adult population, respectively 2.
- However, other studies suggest that higher doses of vitamin D3, between 4000 and 6000 IU/day, may provide greater protection against many adverse health outcomes and achieve serum 25(OH)D levels between 40 and 70 ng/mL 3.
Comparison of Vitamin D2 and D3
Some studies have compared the effectiveness of vitamin D2 and D3 in raising serum vitamin D levels.
- A retrospective cohort study found that vitamin D3 injection alone or with a D2 tablet increased serum vitamin D by 6.1 and 5.6 ng/ml, respectively, whereas vitamin D2 injection alone was associated with the lowest increase in serum concentration by a mean of 3.2 ng/ml 4.
- The study suggests that utilizing vitamin D3 in an injectable form is the best choice to restore severe vitamin D deficiency 4.
Health Effects of Vitamin D Supplementation
The health effects of vitamin D supplementation have been extensively studied.
- While severe vitamin D deficiency should be corrected, supplementation of vitamin D-replete adults does not provide demonstrable health benefits 5.
- However, higher 25(OH)D concentrations have been associated with reduced risks of major diseases and mortality, including pregnancy and birth outcomes, and serum concentrations > 30 ng/mL (75 nmol/L) significantly lower disease and mortality risks compared to <20 ng/mL 3.