What is it?

Vitamin B complex is a type of non-antioxidant vitamin. We don’t fully understand how this type of vitamin may treat arthritis-related conditions, but evidence from trials suggests that vitamins B3, B9 and B12 might be of some benefit for treating osteoarthritis, particularly in improving joint mobility and hand grip. Vitamin B6 may reduce levels of markers of inflammation in rheumatoid arthritis, but there’s no evidence from trials that it improve clinical measures.

  • Family: Nutritional supplement
  • Scientific name: Vitamin B3 (niacinamide), vitamin B12 (Cobalamin), vitamin B9 (folic acid)

Vitamins are nutritional substances which you need in small amounts in your diet. Except for vitamin B12, which can be stored in your liver for up to four years, your body stores all water-soluble vitamins for only a brief period of several weeks to several months and then gets rid of them through the urine. This is why you need to take water-soluble vitamins daily.

Vitamins can be found in foods (natural vitamins) or can be produced in laboratories (synthetic vitamins). You can buy vitamin capsules from high-street shops.

How does it work?

Several studies have found that vitamin B12 plays a role in controlling bone metabolism. Another study found that people with osteoarthritis have low intake of vitamin B9 (folic acid).

Is it safe?

We don’t yet know what the best dose of vitamin B complex is for arthritis and related conditions, but RCTs have used daily doses of 3 g of vitamin B3, 6,400 μg of vitamin B9 and 20 μg of vitamin B12. Vitamin B9 (folic acid) supplements are safe, even with high doses. Apart from occasional gastrointestinal symptoms and itching, vitamin B12 has a high safety profile.

No serious drug interactions have been reported with low or medium intake of non-antioxidant vitamins.

Vitamin B complex trials for rheumatoid arthritis

In this trial‡, 43 participants with rheumatoid arthritis were randomly allocated to receive 5 mg vitamin B9 with or without 100 mg vitamin B6 once a day for 12 weeks.

  • There was no reported difference in change in the disease activity score or number of painful or swollen joints.
  • Those who received the Vitamin B9 and B6 combination demonstrated significantly greater reductions in some markers of inflammation.
  • No side-effects were recorded.

‡ A trial of low quality. Results of this trial were given a lower weighting when we came to our conclusion about the compound.

Vitamin B complex trials for osteoarthritis

Trial 1

In the first trial, 72 people with osteoarthritis were randomly selected to receive either 3 g vitamin B3 or placebo tablets once a day for 12 weeks.

  • Overall symptoms improved by 29% in participants given the vitamin and worsened by 10% in participants on the placebo, although neither group reported a reduction in pain.
  • In particular, vitamin B3 seemed to be effective in improving joint mobility compared to the placebo.
  • No major side-effects were reported, but the number of side-effects was higher in the vitamin B3 group.

Trial 2

In the second RCT, 29 people with hand osteoarthritis were randomised to receive either 6,400 μg vitamin B9, a combination of 6,400 μg vitamin B9 and 20 μg vitamin B12 or placebo tablets once a day for two months. Participants who received vitamin B9 and B12 had significantly better hand grip values compared to the other two treatment groups.