Study: Vitamin D can protect against autoimmune diseases

reference

Hahn J, Cook No., Alexander Ek, ​​et al. Dietary supplements with vitamin D and marine omega-3 fatty acids and occurring autoimmune diseases: randomized controlled vital study. bmj . 2022; 376: E066452.

objective

The effect of a vitamin D and fish oil supplement alone and in combination on the 5-year incidence of newly occurring autoimmune diseases should be examined in an older population

design

randomized, double-blind, placebo-controlled study with a 2 × 2 factor design

participant

25,871 participants took part in this study, including 12,786 men aged ≥ 50 years (51 %) and 13,085 women aged ≥ 55 years. The average age was 67.1 years. People with an earlier diagnosis of kidney failure or dialysis, cirrhosis of the liver, hypercalcaemia, cancer (except non-melanocytic skin cancer), cardiovascular diseases or other serious illnesses were excluded. Of the 25,871 participants, 5,106 blacks and 2,152 were part of other non-white racial and ethnic groups.

intervention

The participants were randomized one of four groups:

1. omega-3 fatty acid (1,000 mg/day; 460 mg eicosapentaenic acid and 380 mg docosahexaenic acid) and vitamin D supplementation (2,000 IE/day)
2. omega-3 fatty acid (1,000 mg/day) and placebo
3. Vitamin D supplementation (2,000 IE/day) and placebo
4. placebo

The participants reported many health results each year for 5 years, and a comprehensive medical examination confirmed the reported diseases.

study parameters

The participants filled up basic questionnaires for lifestyle factors and were interviewed for vitamin D supplementation as well as for eating fish and dairy products. From 16,956 participants, blood samples were removed and examined for 25 hydroxyvitamin D and plasma-omega-3 index. The participants filled out repeated questionnaires 6 months and 1 year after the randomization, then 5 years annually. The participants were questioned specifically to newly occurred, clinically diagnosed rheumatoid arthritis, polymyalgia rheumatica, autoimmune diseases of the thyroid, psoriasis and inflammatory bowel diseases and also received an empty field in which they could enter every new autoimmund diagnosis.

most important knowledge

In older adults, daily taking vitamin D (2,000 IE) reduced the frequency of autoimmune diseases over 5 years. A nutritional supplement with omega-3 fatty acids alone reduced the incidence of autoimmune diseases by 15 %, but was not statistically significant. The combination of vitamin D and omega-3 did not seem to have a significant additional benefit. Omega-3 supplementation alone seemed to be more advantageous in the prevention of the outbreak of an autoimmune disease in people with a positive family history and also seemed to have a greater effect in the later years.

transparency

The National Institutes of Health financed this study, and every author stated that they have no connection to institutions that could possibly draw a financial benefit from the study.

effects on practice

The Vital study was a large randomized, controlled and double-blind study that ran from 2011 to 2017. The primary results of this great company were:

1. Number of participants with invasive cancer of any kind and
2. Number of participants with a serious cardiovascular event (composed endpoint from myocardial infarction, stroke and death due to cardiovascular causes).

The results of this study have led to 25 publications so far, and researchers continue to search for new information on topics such as urinary incontinence, metabolic health and bone density. ^{1 The primary goals of this study provided disappointing results, since the cancer or cardiovascular risk neither through a vitamin D nor by an omega-3-fat serure supplement changed. 2.3}

autoimmune diseases are widespread and seem to be more common. ^{4 While the effects on quality of life, morbidity, mortality and costs vary significantly depending on the specific diagnosis, autoimmune diseases are an essential factor for general human suffering and health costs. These costs increase because new medication such as biologicals become a treatment standard. For example, the treatment of rheumatoid arthritis (RA) costs around $ 29,000 a year, which is typical of serious autoimmune disease. 5 In addition, the experience of an autoimmune disease can have enormous effects on the quality of life and the ability of the individual to participate in activities that are happy to be happy. This study is very welcome because there are only a few large -scale studies on the evaluation of the prevention of autoimmune diseases.}

The Omega-3 result may not be statistically significant because the duration of the study was not sufficient to show the benefits completely.

We are increasingly evidence that a low omega-3 index is a main risk factor for the development of autoimmune diseases such as rheumatoid arthritis. ^{6 There is also indications that the treatment of RA patients with newly occurring rheumatoid arthritis with high-dose (5.5 g), but not with low doses (0.4 g) Omega-3 fatty acids reduce the disease activity values ​​and reduce the escalation of the medication.}

One could argue that this study could not demonstrate any benefits from the omega-3 fatty acid supplement due to the insufficient dosage. This could be a possible bias on the part of the integrative community to expect positive results from a study like this. The authors managed to provide biological evidence that Omega-3 was actually sufficiently dosed. In fact, the omega-3 fatty acid index (Quest Diagnostics) rose 54.7 % to an average of 4.1 % in the first year of the study, which is in the optimal area. The Omega-3 result may not be statistically significant because the duration of the study was not sufficient to completely show the benefits. Interestingly, the researchers found that the Omega-3 effect was more pronounced towards the end of the study and achieved statistical significance with a decline in incidence by 18 % if "probable autoimmune disease" was included.

conclusion

The vital study was a well-designed and comprehensive study in which a diverse population took part and that aimed to evaluate the effects of a vitamin D supplementation, with or without omega-3 supplementation, on the frequency of cancer and cardiovascular diseases. Although there were disappointing results for these end points and for several other secondary endpoints, it seems that vitamin D supplementation, with or without omega-3 supplementation, reduces the incidence of newly occurring autoimmune diseases in humans over 55 years. The study did an excellent job in ensuring the loyalty to therapy by using biomarkers.

There are 3 major challenges. First, many autoimmune diseases occur in younger years than are recorded in this study. Second, many frequent autoimmune diseases such as Hashimoto-thyroiditis can remain for many years before larger clinical symptoms occur, which makes it difficult to distinguish a newly occurring disease. Third, despite the large scope of the study with more than 25,000 participants, there was only a few new diagnoses of an autoimmune disease. For example, only 123 participants of an autoimmune disease appeared in the vitamin D group, compared to 155 in the placebo group. This makes it clear that statements such as "Vitamin D supplementation can reduce the occurrence of autoimmune diseases by 22 %" than they actually are.

This study did not contain any cost analysis. This means that from the public health perspective, you save money to prevent 32 new autoimmune diseases in a population of 25,000 by vitamin D supplementation? Such studies would be particularly helpful for nutritional supplements that are usually not taken over by the insurance. Despite these challenges, this study improves our understanding of the factors that increase the risk of autoimmune disease.