Ascorbic acid increases the severity of spontaneous knee osteoarthritis in a guinea pig model

Abstract

Ascorbic acid has been shown to activate latent TGF beta. Prolonged intraarticular exposure to TGF beta has been shown to cause OA-like changes. We found expression of active TGF beta in osteophytes, a prominent feature of the joint histology seen in association with ascorbic acid treatment. Thus, the deleterious effects of prolonged ascorbic acid exposure may be mediated in part by TGF beta. This worsening of OA with ascorbic acid supplementation suggests that ascorbic acid intake should not be supplemented above the currently recommended dietary allowance (90 mg/day for men and 75 mg/day for women).