A Meta-Analysis of the Impact of Nutritional Supplementation on Osteoarthritis Symptoms

Systematic review and meta-analysis of randomized trials in adults with osteoarthritis, predominantly knee osteoarthritis. The evidence base compared oral nutritional supplements with placebo or active controls across multiple countries.

This review evaluated oral nutritional supplements used for osteoarthritis symptom control, including curcumin 1000 mg/day for 4 to 16 weeks, ginger 250 mg/day for 12 weeks, vitamin D 2000 to 3000 IU/day for 1 or 2 years, vitamin E 400 or 500 IU/day for 3, 8, or 96 weeks, omega-3 for 12 or 24 weeks, and multivitamin or herbal formulations with variable or unreported doses. Comparators were placebo or active controls.

Curcumin and ginger showed the clearest benefit for knee osteoarthritis symptoms. Curcumin improved VAS pain and WOMAC function, with moderate improvement in total WOMAC and a decrease in ESR, although quality of life was not improved and CRP changed inconsistently. Ginger significantly reduced VAS pain (SMD = −3.76, 95% CI −6.88 to −0.65) and lowered ESR and CRP. Vitamin D produced small improvements in VAS pain and WOMAC function, vitamin E showed no significant clinical benefit, and omega-3, multivitamins, and herbal formulations had more limited or mixed effects.

The evidence was heterogeneous in supplement type, dose, duration, and comparator, and many interventions were supported by only a few trials. Several outcomes and inflammatory markers were inconsistently reported, and the data were concentrated in knee osteoarthritis from studies largely conducted in China, Thailand, India, and Iran, which limits generalizability.