Could vitamin D supplements prevent type 2 diabetes?

Share on Pinterest
Studies of vitamin D supplements to prevent diabetes have shown inconsistent results so far. CHAIDEER MAHYUDDIN/AFP via Getty Images
  • Vitamin D deficiency has been linked to an increased risk of several diseases, including type 2 diabetes.
  • Many studies have looked at whether, how much, and what type of vitamin D supplements might help reduce the risk of developing type 2 diabetes.
  • The latest research shows that these studies have largely been inconclusive and that the risk reduction that could be provided by daily vitamin D supplements is small.

Vitamin D deficiency is a growing problem, especially in countries in the northern hemisphere. Likewise, type 2 diabetes is too. This has led some researchers to speculate that there may be a connection between the two.

The proposed mechanism behind this theory is that vitamin D is needed for insulin secretion to be at a healthy level, so a lack of vitamin D could not only put people at risk for type 2 diabetes, but also make it worse. insulin resistance in people with type 2 diabetes.

However, researchers have struggled to prove that vitamin D supplementation could reduce the risk of type 2 diabetes, even in those who have been diagnosed as pre-diabetics.

A meta-analysis published in Diabetic treatments in 2020 found a small risk reduction of around 11% from vitamin D supplementation in people with prediabetes after some high-profile studies failed to show a significant effect.

The latest study, carried out in Japan and published in the BMJalso found no significant effect.

In this multicenter, randomized, double-blind, placebo-controlled trial involving 1,256 participants, researchers sought to measure the effects of daily vitamin D on diabetes risk.

They examined whether 630 participants classified as prediabetic were less likely to develop type 2 diabetes when given 0.75 μg of eldecalcitol, an active vitamin D analogue, daily, compared to a group of 626 participants given a placebo.

They followed the participants for an average of 2.9 years, comparing their fasting blood sugar measurements at the start of the trial and every three months, as well as measurements of glucose tolerance tests taken at the start and then annually. The researchers also looked at the participants’ bone density measurements each year.

Dr Tetsuya Kawahara, lead author of the study from Kitakyushu University of Occupational and Environmental Health, Japan, said Medical News Today that their results were mixed.

The group given eldecalcitol showed a 13% decrease in their risk of developing type 2 diabetes over the study period, but the researchers found that this was not significant.

“Although eldecalcitol (an active analogue of vitamin D) has been shown to prevent the development of type 2 diabetes in our pilot study, its treatment did not show a preventive effect on the incidence of diabetes. type 2 diabetes, nor any beneficial effect on the rate of regression to normoglycemia in this current study,” he said.

However, they found that a certain group seemed to perform better.

“[A]After adjusting for 11 potentially influential factors, including age, sex, blood pressure, body mass index and family history of diabetes, the results suggest that eldecalcitol may prevent type 2 diabetes in patients prediabetics with insufficient insulin secretion,” said Dr. Kawahara.

He said he thinks the reason for the mixed results could be that the study was underpowered.

Dr James Brown of the Aston Research Center for Healthy Aging at Aston University in Birmingham, UK, who studies type 2 diabetes and metabolism, pointed to the same issue.

“The study protocol which was published in 2016 and included a sample size calculation for the primary outcome of diagnosing diabetes which was 750 participants, based on an estimated 36% lower risk , although in the final data the risk was reported at 13%,” he said.

“It is possible that the study was underpowered to detect the primary outcome. It is unclear from the study protocol whether the secondary outcomes are sufficiently powered,” he said. -he declares. DTM.

Dr Tatiana Christides, of Queen Mary University of London, who wrote an accompanying editorial for the study in the BMJsaid that even a small difference in risk of developing type 2 diabetes could be significant at the population level because many people have prediabetes.

“Depending on the literature you read, there is a 5 to 10 percent risk of progression in people with prediabetes,” she said. DTM in an interview.

She went on to explain with an example:

“Let’s say there are 100 people with prediabetes, and every year 10 of them will develop full-blown diabetes. This means that you would prevent 1 of those 10 people from becoming full-blown diabetics. It is, at the level of public health, [s]meaningful,” she said.

However, Dr Christides also said she was concerned about advising people to take vitamin D to prevent the development of type 2 diabetes. Without strong evidence, this could deter people from trying risk-reducing interventions. , such as weight loss, for which there is much stronger evidence, she added.

Comments are closed.