Does Vitamin D Prevent Autoimmune Disease?

Up to 75% of American teens and adults are said to be deficient in vitamins D and E, but there is no consensus on how much is deficiency. There are many claims for the health benefits of taking vitamins D and D3.

A study of vitamins D and fish oil in the British Medical Journal has been getting a lot of press, with claims that it can be used to prevent disease, and a prediction that doctors may soon recommend vitamins D and fish oil for all adults over the age of 50. I didn't expect much when I read the study, but I've become tired of news reports that try to hype it as proof of causality. The study did not provide convincing evidence that everyone should take supplements.

There is a study.

A large, randomized, placebo-controlled evaluation of two supplements was done. During the study, patients self- reported new diagnoses of autoimmune diseases, and these diagnoses were reviewed for accuracy by doctors.

There were findings.

 Vitamin D supplementation for five years, with or without omega 3 fatty acids, reduced autoimmune disease by 22%, while omega 3 fatty acid supplementation with or without vitamin D reduced the autoimmune disease rate by 15% (not statistically significant).

There are some conditions.

The majority of participants were healthy.

The recommended daily amount of vitamins D and E was higher than the dose.

There was no benefit for any disease.

The study has not been confirmed by other research.

The relative risk reduction was 22%. The number of vitamins needed to treat would be high if they were being used to reduce the risk of autoimmune diseases.

Since there was no statistical correction for multiple comparisons and most of the ancillary studies had negative results, one false positive result could be expected.

There are a lot of unanswered questions.

We don't know who is most likely to benefit from a deficiency of vitamins D and D and what dose they will need. Better guidance will be provided by more research. It seems clear that the evidence doesn't support giving it to everyone. The data was overwhelmed by media enthusiasm.