Vitamin D supplementation in the management of knee osteoarthritis: study protocol for a randomized controlled trial
Cao Y et al. – The trial is designed to test if vitamin D supplementation will reduce loss of knee cartilage volume, prevent the progression of other knee structural abnormalities, reduce knee pain and strengthen lower limb muscle strength, thus modify disease progression in knee Osteoarthritis (OA).
- Randomised, placebo–controlled, and double–blind clinical trial aiming to recruit 400 subjects (200 from Tasmania and 200 from Victoria) with both symptomatic knee OA and vitamin D deficiency (serum [25–(OH)D] level of >12.5 nmol/liter and <60 nmol/liter).
- Participants will be randomly allocated to vitamin D supplementation (50,000 IU compounded vitamin D3 capsule monthly) or identical inert placebo group for 2 years.
- The primary endpoint is loss of knee cartilage volume measured by magnetic resonance imaging (MRI) and Western Ontario and McMaster Universities Index of OA (WOMAC) knee pain score.
- The secondary endpoints will be other knee structural changes, and lower limb muscle strength.
- Several other outcome measures including core muscle images and central blood pressure will be recorded.
- Linear and logistic regression will be used to compare changes between groups using univariable and multivariable modeling analyses.
- Both intention to treat and per protocol analyses will be utilized.