The effects of vitamin C supplementation on incident and progressive knee osteoarthritis: a longitudinal study

Public Health Nutr. 2011 Apr;14(4):709-15. doi: 10.1017/S1368980010001783. Epub 2010 Aug 16.


Objective: To evaluate the association between vitamin C supplementation and the incidence and progression of radiographic knee osteoarthritis (OA).

Design: Prospective cohort study.

Setting: Clearwater Osteoarthritis Study (COS): (1988 to the present) a longitudinal study.

Subjects: Male and female COS participants aged 40 years and above (n 1023). The study exposure was the participants' self-reported history of vitamin C supplementation. The participants underwent biennial, sequential knee radiographs, which were assessed using the Kellgren-Lawrence ordinal scale to determine evidence of the study 2 outcomes: incident radiographic knee OA (RKOA) and progression of RKOA.

Results: Individuals without baseline knee OA who self-reported vitamin C supplement usage were 11% less likely to develop knee OA than were those individuals who self-reported no vitamin C supplement usage (risk ratio (RR)=0.89, 95% CI 0.85, 0.93). Among those participants with RKOA at baseline, vitamin C supplement usage did not demonstrate an association with RKOA progression (RR=0.94, 95% CI 0.79, 1.22).

Conclusions: In the present prospective cohort study, we found no evidence to support a protective role of vitamin C in the progression of knee OA. However, after controlling for confounding variables, these data suggest that vitamin C supplementation may indeed be beneficial in preventing incident knee OA. Given the massive public health burden of OA, the use of a simple, widely available and inexpensive supplement to potentially reduce the impact of this disease merits further consideration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Antioxidants / administration & dosage*
  • Ascorbic Acid / administration & dosage*
  • Cohort Studies
  • Dietary Supplements / statistics & numerical data*
  • Disease Progression
  • Female
  • Humans
  • Incidence
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Osteoarthritis, Knee / diagnostic imaging
  • Osteoarthritis, Knee / epidemiology*
  • Osteoarthritis, Knee / prevention & control*
  • Prospective Studies
  • Radiography
  • Self Disclosure


  • Antioxidants
  • Ascorbic Acid