Vitamin D is a nutrient that plays many roles in the immune system and central nervous system. For example, the benefits of vitamin D include anti-inflammatory and immunoregulatory effects, partly by activating the immune response and improving the function of immune cells (including T cells and macrophages).
It is believed that a higher intake of vitamin D, both from natural sunlight and dietary sources, as well as supplements, provides protection against infections, viruses, and also against certain immune-related disorders.
Can low levels of Vitamin D cause an autoimmune disease? Recent research suggests that this could be a possibility.
While vitamin D deficiency may not directly cause immune-related diseases, a link has been found between low levels of vitamin D and the development of autoimmune diseases.
Study: Vitamin D and Autoimmune Diseases
A 2022 study published in the BMJ aimed to determine whether vitamin D and omega-3 fatty acids could reduce the risk of autoimmune diseases. The study was a randomized, double-blind, placebo-controlled trial conducted in the USA over more than five years and included over 25,000 participants aged over 50.
The study concluded:
Supplementation with vitamin D for five years, with or without omega-3 fatty acids, helped reduce autoimmune diseases by 22%.
Supplementation with omega-3 fatty acids, with or without vitamin D, helped reduce the rate of autoimmune diseases by 15%. (This was considered statistically insignificant.)
Both treatments showed greater effects than placebo.
Supplementation with both vitamin D and omega-3 fatty acids helped reduce autoimmune diseases by approximately 30% compared to placebo administration.
The incidence of rheumatoid arthritis was about 40% lower in the supplement groups than in the placebo group.
The study was designed so that participants received vitamin D supplements (1,25-dihydroxyvitamin D) in doses of 2,000 IU/day or appropriate placebo, and omega-3 fatty acids (derived from marine sources) in doses of 1,000 mg/day or appropriate placebo. Participants self-reported all autoimmune diseases during the study, which were then confirmed by medical reviews.
The autoimmune diseases identified in participants included:
rheumatoid arthritis
polymyalgia rheumatica
autoimmune thyroid diseases
psoriasis
For the vitamin D group, 123 participants in the treatment group, compared to 155 in the placebo group, had a confirmed autoimmune disease.
In the omega-3 fatty acid group, 130 participants in the treatment group, compared to 148 in the placebo group, had a confirmed autoimmune disease.
In the placebo-only group, it was confirmed that 88 developed autoimmune diseases. Among participants who received vitamin D and omega-3 fatty acids, 63 developed autoimmune diseases, while 60 who received only vitamin D and 67 who received only omega-3 fatty acids had confirmed autoimmune diseases.
What do these results mean?
The above-mentioned BMJ study showed that a higher intake of vitamin D had the strongest effects in preventing autoimmune diseases. Omega-3s also reduced the risk of autoimmune issues, but not as effectively as vitamin D.
How does vitamin D help autoimmune diseases?
Autoimmune diseases are chronic conditions characterized by inflammatory autoimmune responses to one’s own tissues. In other words, they occur when the immune system begins to attack the body.
Vitamin D is believed to protect against autoimmune diseases through various mechanisms:
Regulating a number of genes, many involved in inflammation
Suppressing inflammatory cytokines and chemokines (including C-reactive protein and IL-6)
Inhibiting the production of autoantibodies for B cells and promoting the differentiation of monocytes into macrophages (other ways to reduce inflammation)
Increasing the production of anti-inflammatory regulatory T cells
Can vitamin D exacerbate autoimmune diseases?
It is unlikely, except in cases where someone takes very high amounts of vitamin D. As long as you follow recommendations, vitamin D should not worsen immune-related health issues.
How much vitamin D should you take if you have an autoimmune disease?
Aim for about 1,000 to 2,000 IU per day. In the study described above, adults were given 2,000 IU/day.
Remember to stay consistent, as most protective effects were found after two years of supplementation.
Other ways to combat/prevent autoimmune issues
Follow an anti-inflammatory diet to support gut health.
Identify if you have allergies/intolerances, such as gluten or dairy.
Reduce environmental risk factors, such as exposure to toxins, infections, and stress.
Get enough sleep and rest.
Exercise regularly.
Combat oxidative damage caused by free radicals by avoiding smoking and excessive alcohol.
What are the best vitamins for autoimmune diseases?
Experts believe that people with autoimmune diseases can benefit most from:
Vitamin D
Omega-3
Curcumin
Glutathione
L-glutamine
A quality multivitamin complex
Antioxidants, such as resveratrol (the same type found in berries and red wine)
Are omega-3s good for autoimmune diseases? Do omega-3s reduce inflammation?
Yes, as explained above, studies suggest that a higher intake of omega-3s may help protect against the development of autoimmune diseases. It is well known that, in general, the benefits of omega-3s can include combating inflammation, supporting healthy blood flow, and much more.
That said, supplementation with only omega-3s did not significantly reduce the incidence of autoimmune disease in the BMJ study. This means you should focus on other healthy lifestyle changes, including improving your diet and taking vitamin D.
On a positive note, other randomized controlled studies on individuals with prevalent rheumatoid arthritis, systemic lupus, and psoriasis have shown improvements in symptoms when taking omega-3s. For example, an observational study found a 49% reduction in the risk of rheumatoid arthritis for every increase of 30 grams in daily fat intake.
What supplements should I avoid if I have an autoimmune disease?
Be cautious if you are using very high doses of vitamin C (too much is not always better), high doses of vitamin A/beta-carotene, and certain herbs long-term, such as echinacea and ginseng.
All of these can be helpful in the short term or in moderate doses, but depending on the immune system and sensitivities, you may not benefit from them when taken for long periods.
Conclusion
Should I take vitamin D if I have an autoimmune disease? Research suggests yes, you should.
A recent study found that supplementation with vitamin D and omega-3 fatty acids has protective effects against autoimmune diseases (including rheumatoid arthritis, polymyalgia rheumatica, autoimmune thyroid diseases, and psoriasis).
In this large study, supplementation with vitamin D and omega-3s for five years was linked to a lower incidence of confirmed autoimmune disease compared to placebo.
A link was specifically found between low levels of vitamin D and the development of autoimmune diseases, as vitamin D helps combat inflammation in multiple ways.
Do omega-3s suppress the immune system? No, omega-3s should help with symptoms of autoimmune diseases in most cases, but you should still make lifestyle changes to support your immune system.
