Vitamin D can modestly reduce knee arthritis pain at the right dose. Here’s what the trials show — and why other supplements may work better.

Written by Dr. Jeffrey Peng, MD — Board-Certified Sports Medicine Physician Published: March 1, 2026 | Last Updated: March 1, 2026 Knee arthritis is one of the most common conditions I treat in my sports medicine practice, and one of the most frustrating things patients experience is how unpredictable it can be. Two patients with nearly identical X-rays can have completely different levels of pain, function, and long-term outcomes. For years, we've treated osteoarthritis wit