Vitamin D improves the absorption of calcium and phosphorous, and helps in the maintenance of bone health. Osteoporosis Canada's guideline statements recommend a daily vitamin D intake of 400-1000 IU for low-risk adults under 50 years of age and 800-2,000 IU for high-risk and older adults.1
Vitamin D intakes of 700-800 IU/day are associated with a decreased risk of bone fracture, in comparison with 400 IU/day.2