Vitamin C & Arthritis

What is Vitamin C?

Vitamin C is a water-soluble vitamin and an essential nutrient in most animal species including humans. It is also known as ascorbic acid and its active form is L-ascorbate.

Vitamin C is required as a cofactor in a number of biochemical reactions and it is also an important antioxidant. While humans cannot synthesize vitamin C, most animals do and in large amounts too. Therefore, some have advocated that megadoses of vitamin C supplements should be routinely taken by humans.

Ascorbic acid is a weak acid and a sugar-like molecule which has a structure similar to that of glucose. It is transported all over the body either as L-ascorbic acid (found in acidic pH) or its ion, L-ascorbate (found in pH 5 and above).

Vitamin C is a reversible antioxidant.

This means that it can be regenerated after reducing oxidative free radicals or bioactive molecules in the body. However, instead of splitting into a free radical itself, the ascorbic acid molecule is reformed in a unique mechanism that makes vitamin C a safe, reversible antioxidant.

Vitamin C is essential for the production of collagen and neurotransmitters such as norepinephrine. It also inhibits histamine release and activity as well as act as immune system booster.

A deficiency of vitamin C causes scurvy which is malformation of collagen. Therefore, this deficiency can cause pigmentation of the skin, open and bleeding wounds on the skin and mucosal membranes and reduced mobility caused by degeneration of the cartilage since collagen makes up the connective tissues at the joints.

Vitamin C: Supplementation, Sources and Side Effects

Recommended daily intakes of vitamin C varies by country and health organization.

For example, the World Health Organization (WHO) recommends 45 mg per day while the National Academy of Sciences of the United States recommends 60 – 95 mg per day.

The upper tolerable limit of vitamin C is placed at 2000 mg per day. However, since it is a water-soluble vitamin, vitamin C toxicity is difficult to achieve.

Dietary sources of vitamin C include plants and animals. However, the richest sources of the vitamin are fruits, vegetables and raw livers.

Vitamin C supplements are the most popular nutritional supplements taken. They are available as tablets, caplets, capsules, crystals, powders, fortified foods and drinks as well as in multivitamin formulations.

The most common side effect of high doses of vitamin C is diarrhea.

Vitamin C also enhances the absorption of iron. Therefore, it may cause iron poisoning in people with iron overload disorders.

Megadoses of vitamin C exceeds the amount needed for routine supplementation and is, therefore, termed as a therapeutic use of the vitamin. Proponents of megadoses of vitamin C argue that other animals produce a very high amount of the vitamin daily and especially during periods of stress.

How Vitamin C Helps Arthritis Joint Pain

Vitamin C can help reduce joint pain due to arthritis by 2 major mechanisms: its antioxidant property and its contribution to the stability and synthesis of collagen.

The Antioxidant Effect

Vitamin C is one of the most important antioxidants for humans. It is the reason it is highly demanded by the body to combat stress.

In fact, vitamin C is both an antioxidant and an immune booster.

As an antioxidant, vitamin C prevents oxidative stress. Oxidative stress refers to the harmful effects of reactive oxygen species produced during normal metabolism. These superoxides or free radicals can cause and worsen different diseases in the body. They are linked to heart problems, diabetes and chronic inflammation.

The reactive oxygen species can damage the synovial membrane. This causes the synovial fluid, which lubricates the bones at the joint, to leak. These free radicals can also directly damage the cartilage, causing it to degenerate and dehydrate.

The overall result of these oxidants on the joint is the loss of the lubricant and cushioning effects supplied by the synovial fluids and the cartilage respectively. This causes the bone heads at the joint to wear against each other.

Without lubrication and cushioning, movement with the affected limbs becomes painful.

 However, the antioxidant property of vitamin C can help improve the articulation of joints by preventing the oxidative damage of the free radicals.

By sparing the cartilage and synovial membrane, vitamin C preserves the integrity of the joint and so reduces joint pain and even inflammation.

The Collagen Effect

Vitamin C plays an important role in the synthesis of collagen. It is needed early on during the production of the precursor to collagen, procollagen.

Experiments have shown that vitamin C is needed for the production of procollagen from the amino acids, proline and glycine. When vitamin C is added to the in vitro cultures of connective tissues, the production of vitamin C is increased 8-folds.

Specifically, vitamin C is needed as a cofactor for the enzymes responsible for the 3-dimensional crosslinking of procollagen. Ultimately, this is the step that gives collagen its structurally strength.

This step is also the reason that unstable collagen is formed in people with vitamin C deficiency.

With its great tensile strength, collagen fibrils are the main components of bones, skins, ligaments, cartilages and tendons.

Given that collagen is needed for ligaments, cartilages and tendons, its synthesis is central to the nature of joints.

Therefore, vitamin C deficiency can lead to improperly formed and unstable collagen. When this malformed collagen is incorporated into cartilages and ligaments, these connective tissues are easily damaged.

Vitamin C is required for properly formed cartilages and ligaments. It can contribute to the rejuvenation of degenerated cartilages and ligaments. Therefore, it can reduce joint pain and even help rebuild lost cartilage.

Studies on the Use of Vitamin C in Arthritis Management

Vitamin C can be quite helpful in the treatment of different forms of arthritis. It has been shown to improve pain due to gout arthritis because vitamin C reduces the serum level of uric acid.

Other studies show that the ability of vitamin C to reduce the risk of gout and joint pain due to this form of arthritis increases with increasing doses of the vitamin.

However, vitamin C can also reduce other kinds of joint pain not associated with arthritis. In a 2007 paper published in the American volume of The Journal of Bone and Joint Surgery, the effectiveness of vitamin C for treating complex, regional pain syndrome was evaluated.

The prospective, randomized, multicenter study recruited 416 patients who reported 427 wrist fractures were treated with one of 200 mg, 500 mg, 1500 mg of vitamin C or placebo daily for 50 days.

The result showed that all doses of vitamin C reduced wrist joint pain and that even though 1500 mg produced a better pain reduction, it was only slightly better than 500 mg daily doses of the vitamin.

In another study published in Annals of Rheumatic Diseases, 23,000 participants in a large-scale cancer study in which their diets were recorded over a period of 8 years. The study result showed that participants who ate more vitamin C-rich fruits and vegetables had lower risks of developing rheumatoid arthritis.

How to Take Vitamin C for Joint Pain

Although vitamin C is acidic by nature, there are specially formulated non-acidic forms of the vitamin.

Most ascorbate salts, such as calcium ascorbate, are non-acidic forms of vitamin C. These non-acid vitamin C forms do not cause gastrointestinal irritation and they actually provide better results than the acidic forms.

Vitamin C supplements are especially recommended for arthritis patients who take aspirin and non-steroidal anti-inflammatory drugs (NSAIDs) for joint pain. NSAIDs such as ibuprofen can reduce the levels of vitamin C in the body.  Therefore, vitamin C supplements should be taken alongside both to prevent a deficiency in the vitamin and also to improve the analgesic effect of the NSAID.

On the other hand, high doses of vitamin C reduce the elimination of acetaminophen from the body.

Therefore, care should be taken by patients treating joint pain with acetaminophen. For such patients, low doses of vitamin C are advised in order to reduce the risk of acetaminophen buildup and toxicity.

While high-strength vitamin C may provide marginally better relief for joint pain, the risks of overdose and other complications may outweigh the benefits. Therefore, megadoses of vitamin C are not advised for treating joint pain.

In fact, a preliminary study done with animal models suggest that high doses of vitamin C may increase the risk of osteoarthritis even though it reduces the risk of developing rheumatoid arthritis.

Therefore, the best benefits are obtained with 250 – 1000 mg per day of vitamin C.