The Effects of Vitamin C on Arthritis

Studies show conflicting findings for osteoarthritis and RA

Oranges and juicer.
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An arthritis prevention or management plan has many facets, all of which work together to control disease progression and/or ease symptoms. Nutrition plays into this, and vitamin C has been investigated for the role it may play in these efforts. While experts agree that vitamin C is important, studies on the matter conflict as to the role it can play in arthritis.

Vitamin C and Osteoarthritis

Osteoarthritis (OA) is characterized by a gradual deterioration of the joints, the main reason it is also referred to as the wear-and-tear arthritis.

Study results reported in the June 2004 edition of Arthritis & Rheumatism found that the long-term use of vitamin C may worsen the severity of osteoarthritis of the knee. The animal study from researchers at Duke University in Durham, North Carolina, analyzed the effect of eight months of low, medium, and high doses of vitamin C in guinea pigs.

Guinea pigs, much like humans, are unable to synthesize vitamin C for themselves. The low dose was the minimum amount necessary to prevent scurvy (a disease resulting from the lack of vitamin C) while the medium dose of 30 milligrams per day was comparable to a person consuming five fruit and vegetable servings daily. The highest dose was a daily amount of 150 milligrams, an amount the researchers believed could protect against the surgically-induced osteoarthritis.

The researchers found an association between the high levels of vitamin C and increasing collagen in knee cartilage. Collagen is a critical component of many connective tissues in the body. However, the researchers also found that high levels of vitamin C promoted bone spurs and increased joint damage.

Based on the examination of specimens taken from the knee joints of the animal subjects, the researchers found that the high-dose group developed the most severe osteoarthritis of the knee and the worst cartilage damage.

While animal study results may not exactly translate to humans, the study results suggest that dietary intake of vitamin C should not be supplemented above the current recommended dietary allowance (RDA).

Vitamin C RDA for Women

  • 90 mg

Vitamin C RDA for Men

  • 75 mg

Vitamin C and Rheumatoid Arthritis

Rheumatoid arthritis is an autoimmune disease that leads to inflammation of the lining of the joints, resulting in destruction and deformity of the affected joints.

According to a June 2004 study with results published in the Annals of the Rheumatic Diseases, consumption of foods high in vitamin C is associated with a reduced risk of developing inflammatory polyarthritis, which includes rheumatoid arthritis (RA). This population-based, case controlled study of residents of Norfolk, United Kingdom, consisted of men and women ages 45 to 74 who were followed from 1993 to 2001. All the participants kept food diaries and were arthritis-free at the study onset.

Seventy-three participants went on to develop inflammatory polyarthritis during the eight-year period while 146 remained arthritis-free. After analysis, researchers concluded that the study participants who developed arthritis ate fewer fruits and vegetables than those who did not develop the disease. Participants who ate the least fruits and vegetables had twice the risk of developing inflammatory arthritis.

There was also a significant difference in how much vitamin C the people with arthritis consumed compared to those who did not develop arthritis. Participants who consumed the lowest amounts of vitamin C were three times more likely to develop the arthritic condition than those who consumed the highest amounts of vitamin C.

Vitamin C might protect against the development of polyarthritis and RA for a variety of reasons.

  • Vitamin C is a powerful antioxidant that fights molecules that trigger inflammation.
  • Vitamin C serves a role as a co-factor in collagen synthesis, the main protein in joint tissue and bone.
  • Vitamin C plays a role in fighting infection and may work to control inflammation linked to infection.
  • Some believe infection can trigger flares of rheumatoid arthritis.

A Word From Verywell

There is no denying that vitamin C benefits everybody, whether they have arthritis or not. Therefore, it is a good idea to maintain a healthy balance of vitamin C-rich foods, including citrus fruits, kale, strawberries, raspberries, and red peppers. Talk to your doctor about a vitamin supplement if you struggle to get enough vitamin C from your diet. 

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Article Sources

  • Kraus VB, Huebner JL, Stable T, et al. Ascorbic acid increases the severity of spontaneous knee osteoarthritis in a guinea pig model. Arthritis Rheum. 2004; 50 (6): 1822–1831. DOI: 10.1002/art.20291

  • National Institutes of Health. Vitamin C Fact Sheet for Health Professionals. Updated September 18, 2018.

  • Pattison D, Silman A, Goodson N, et al. Vitamin C and the Risk of Developing Inflammatory Polyarthritis: Prospective Nested Case-Control Study. Ann Rheum Dis. 2004 Jul; 63(7): 843–847. DOI: 10.1136%2Fard.2003.016097