According to Mayo Clinic, adults up to age 70 should aim for 600 IU of vitamin D daily, while adults older than 70 should aim for 800 IU.
Notes on verification
Directly confirmed by Mayo Clinic's own page and corroborated by NIH, Harvard Nutrition Source, and Harvard Health, all tracing back to the Institute of Medicine's 2011 Dietary Reference Intake guidelines. [tier=silver indep_score=0.735 clusters=2 claim_tier=everyday]
Sources
- Aging: What to expect (seed:health_and_medicine)
- https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/ (corroboration)
- https://nutritionsource.hsph.harvard.edu/vitamin-d/ (corroboration)
- https://www.health.harvard.edu/diet-and-nutrition/taking-too-much-vitamin-d-can-cloud-its-benefits-and-create-health-risks (corroboration)