Light Up Your Health with Vitamin D

Vitamin D does way more than you think — and most people don't have enough. Dr. Lewis and Becca break down the science connecting vitamin D to pain, joint health, immunity, and autoimmune disease. Plus: injectable vitamin D, the Harvard VITAL trial, and why "normal" lab ranges aren't good enough.KEY SOURCESWu Z, et al. Vitamin D concentration and pain: systematic review and meta-analysis (81 studies, 50,000+ participants). Public Health Nutr. 2018. https://doi.org/10.1017/S1368980018000551Hahn J, et al. Vitamin D and omega-3 supplementation and incident autoimmune disease: VITAL randomized controlled trial (25,871 participants). BMJ. 2022. https://doi.org/10.1136/bmj-2021-066452Rexhepi-Kelmendi B, et al. Vitamin D supplementation on disease activity and pain in rheumatoid arthritis: randomized double-blinded controlled study. BMC Rheumatol. 2025. https://doi.org/10.1186/s41927-025-00543-6OA Initiative database analysis: vitamin D and knee osteoarthritis pain. Sci Rep. 2024. https://doi.org/10.1038/s41598-024-81845-6Oral vs. intramuscular vitamin D replacement in adults with deficiency. J Clin Diagn Res. 2016. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5240054/TARGET-D trial: tailored vitamin D dosing and recurrent heart attack risk. Presented at AHA Scientific Sessions 2025, New Orleans. https://newsroom.heart.org