- Researchers studied the effects of vitamin D on systematic low-grade inflammation.
- They found that vitamin D deficiency leads to higher levels of inflammatory biomarkers.
- They concluded that improving vitamin D status in deficient patients could reduce their risk or severity of chronic diseases with inflammatory components.
Systematic low-grade inflammation is characterized by the sustained release of inflammatory molecules and is
While vitamin D is classically known to regulate calcium levels, recent
For example, research has linked blood vitamin D concentrations to levels of C-reactive protein (CRP), a widely used inflammatory biomarker.
However, it is still unknown whether low levels of vitamin D increase CRP levels, as shown in randomized studies.
Recently, researchers examined the evidence for the influence of vitamin D levels on CRP levels in a new study.
Researchers have reported a direct link between low vitamin D levels and higher CRP levels. They say their findings could provide an important biomarker to identify people at risk for inflammatory diseases.
“There is growing evidence that improving vitamin D status reduces the risk of autoimmune diseases, including type 1 diabetes, multiple sclerosis and other inflammatory disorders such as type 1 diabetes. 2 and cardiovascular diseases”, Dr. Michael F. Holickprofessor of medicine at Boston University School of Medicine, who was not involved in the study, said Medical News Today.
“This is also consistent with the recent observation of the
The study was published in the International Journal of Epidemiology.
For the study, the researchers looked at data from 294,970 unrelated people of White-British ancestry from the UK Biobank.
Health data included serum 25-hydroxyvitamin D or 25(OH)D levels – a standard measure of vitamin D – and CRP concentrations alongside genetic data.
The average concentration of 25(OH)D was 50 nmol/L, while 11.7% had concentrations below this deficiency threshold of 25 nmol/L.
Participants also completed questionnaires providing information about their health and lifestyle.
After analyzing the data, the researchers found that among the participants, only those who lacked vitamin D had high levels of CRP.
They also found that increasing vitamin D levels in deficient patients can help lessen the severity of inflammation.
The researchers noted that this supports a previously proposed threshold effect, which suggests that correcting vitamin D deficiency can reduce low-grade inflammation and potentially mitigate the risk of inflammation-related disease.
The researchers further noted that the genetically predicted CRP concentration did not appear to affect vitamin D levels in linear and nonlinear statistical analyses.
When asked how vitamin D levels might influence inflammation levels, Dr. Elina Hypponenprofessor of nutritional and genetic epidemiology at the University of South Australia, one of the study’s authors, said DTM:
“In cellular and animal experiments, hormonal vitamin D inhibits the production of inflammatory cytokines such as interleukin-12 (IL-12).”
In the article, the researchers noted that vitamin D may also promote the production of IL-10, an anti-inflammatory cytokine.
Dr. Bruce Hollisprofessor of pediatrics at the Medical University of South Carolina, who was not involved in the study, agreed with Professor Hypponen and noted that “these are well-known vitamin D checkpoints in the cellular level”.
“To say vitamin D is an important immune regulator is an understatement,” he said. DTM.
The researchers concluded that improving vitamin D status in the deficiency range could reduce low-grade systemic inflammation and potentially mitigate the risk of inflammation-related diseases.
Asked about the limitations of the study, Professor Hypponen noted that their study only investigated the effects of vitamin D on CRP and could not be used to confirm the mechanisms underlying this link.
Asked about the limitations of the study, Dr. Nik Tsotakosassistant professor of biology at Pennsylvania State University, who was not involved in the study, said DTM:
“The study is very well done, and it is important to note that the data comes from a cohort of hundreds of thousands of individuals. The limitation I can identify from the study is that inflammation was determined exclusively by CRP levels which, although a sensitive marker, is not specific.
He noted that more at the molecular, cellular and tissue level is needed to understand how vitamin D levels are linked to autoimmune diseases.
Dr David Cutlera family physician at Providence Saint John’s Health Center in Santa Monica, Calif., who also was not involved in the study, pointed out that the effects of vitamin D are an “ongoing area of controversy.”
“In fact, even the supposed bone-enhancing properties of vitamin D have been called into question by a recent major study of over 25,000 people followed for over 5 years showing no reduction in fracture risk when taking vitamin D. So what should we conclude from a recent study showing an association between lower levels of vitamin D and higher levels of the c-reactive protein inflammation indicator? Probably not much,” he said MNT.
This, Dr. Cutler said, is because association is not the same as causation.
For example, he noted that low vitamin D levels in COVID patients may not mean that low vitamin D levels alone increase the risk of COVID-19. He said that’s because people who are usually sick, stay indoors and get sick from COVID-19 are less likely to be exposed to the sun, which could boost their vitamin D.
He further noted that there is some uncertainty as to the definition of what constitutes low vitamin D because “there has been no direct attribution of adverse effects of vitamin D between 20 and 30”.
“Obviously, a profound vitamin D deficiency can lead to abnormal bone formation (rickets) in children and osteoporosis in adults. However, it has never been proven that subtle deficiencies, although associated with many conditions, directly cause or contribute to disease,” he said.
“Supplementing children’s diets – cereals and cow’s milk – virtually eliminated rickets, while osteoporosis and fractures in the elderly had little to no impact from vitamin D supplements. And there always has the risk that too much vitamin D will cause kidney damage and bone pain.
— Dr. David Cutler
When asked if it might be important for people to check whether they are clinically deficient in vitamin D before taking supplements, Dr. Hollis shared his own recommendation:
“I would recommend taking a vitamin D supplement daily. Personally, I recommend a circulating level of 25(OH)D at 50 ng/ml. Again, personally, I take a 10,000 IU/day supplement, as does my entire family, and we have had no problems doing so for the past 15 years. One can do a blood test, but taking the supplement is easy and safe.
Dr. Tsotakos however noted: “There is very little or no benefit in terms of CRP levels from vitamin D supplementation for people who have serum 25(OH)D levels above 30 nmol. /L, which is the lower limit of the reference range. . This means that people who are clinically deficient are more likely to benefit from vitamin D supplementation.”
“Generally, over-the-counter vitamin D supplements contain relatively low doses that are overall very safe. That said, supplements are often taken by people who don’t actually need them, as most would be. people who lead active lives during the summer,” added Dr. Hypponnen.
If in doubt, a blood test could help determine if you have a deficiency.
“From late fall to late spring, it can be helpful to take a little extra vitamin D. Although, for safety reasons, blood tests are generally not necessary when taking the type of doses recommended in public health guidelines, if you want to make sure you are not eating supplements without any benefit, a test blood will help you.
— Dr. Elina Hypponen