A new study published in the journal BMC Medicine has found that vitamin D deficiency is associated with a long list of immune mediated diseases.
Vitamin D deficiency has been linked to immune-mediated diseases before. There is average to good evidence that vitamin D deficiency plays a role in the diseases multiple sclerosis, type 1 diabetes (T1D), inflammatory bowel disease, rheumatoid arthritis, systemic lupus erythematosus and Sjogren’s syndrome.
In the present study, researchers led by Dr Sreeram V Ramagopalan of the University of Oxford wanted to know if vitamin D deficiency correlated with immune-mediated diseases in the hospital setting.
They searched medical records for all patients admitted to an English National Health Service hospital, specifically looking for patients that were medically coded for vitamin D deficiency or the severe vitamin D deficiency diseases rickets and osteomalacia. For those without a medical background, health care professionals use international standardized codes to classify diseases and conditions. For instance, if you have asthma, health care professionals will classify your condition with the code J45. Vitamin D deficiency is E55.9.
The researchers then looked at what diseases these patients coded for vitamin D deficiency suffered from. And they matched these vitamin D deficient patients with controls, patients admitted to the hospital that weren’t suffering from vitamin D deficiency, rickets or osteomalacia. In total, they had records for 19,338 patients with vitamin D deficiency (13,260 with vitamin D deficiency only, 1,228 with rickets and 5,191 with osteomalacia). They matched these patients with 8,605,952 controls.
They wanted to know, in the hospital setting, if you’re admitted with vitamin D deficiency, are you more or less likely to have certain diseases than those not admitted with vitamin D deficiency?
Here’s what they found:
- The researchers found a laundry list of immune-mediated diseases associated with vitamin D deficiency. Compared to controls, if you were coded for vitamin D deficiency, you had an increased risk of having Addison’s disease, ankylosing spondylitis, autoimmune hemolytic anemia, chronic active hepatitis, celiac disease, Crohn’s disease, type 1 diabetes, pemphigoid, pernicious anemia, primary biliary cirrhosis, rheumatoid arthritis, Sjogren’s syndrome, systemic lupus erythematosus, and thyrotoxicosis. All of these conditions were statistically significant.
- In a surprise finding, if you were coded for vitamin D deficiency, you had a decreased risk of having asthma and myxedema.
The researchers conclude,
“We present evidence associating vitamin D deficiency with risks of or protection against developing subsequent immune-mediated disease.”
There are limitations of the study, however. It is cross-sectional in design, so we can’t say for sure whether vitamin D deficiency is causing these diseases, or these diseases are causing vitamin D deficiency. For instance, in Celiac disease, these patients may just not be able to absorb dietary vitamin D very well, thus leading to vitamin D deficiency. Or if you’re suffering from something like lupus, you may be less likely to go outside.
Regardless of limitations, this was an interestingly designed study that warrants further investigation. There is already higher quality research underway looking at the role of vitamin D in the prevention and treatment of some of these diseases, like Crohn’s, type 1 diabetes, rheumatoid arthritis and lupus. This present research could spark interest in the role of vitamin D in some of the lesser studied diseases found to be associated with vitamin D deficiency in this study.
Regardless of whether vitamin D deficiency causes these diseases or these diseases cause vitamin D deficiency, vitamin D deficiency should be treated and monitored. At the very least, this study provides evidence that patients with these diseases are at risk for vitamin D deficiency and should be treated accordingly. Further research will clarify if vitamin D sufficiency has any prevention or treatment effect for these diseases.