Vitamin D Pills Could Slow Progress of Type 2 Diabetes, Prediabetes, Scientists Say

People with prediabetes and newly diagnosed type 2 diabetes may be able to slow the progress of the condition by taking vitamin D, scientists believe.

Consuming the molecule could help the body metabolize glucose according to the authors of a study published in the European Journal of Endocrinology. The work builds on studies which shows there is a worldwide problem with vitamin D deficiency, and link the deficiency to an inability to process sugar.

The study involved 96 participants who were at high risk of diabetes, or who had recently been diagnosed with type 2. Researchers asked one group to take 5,000 IU of vitamin D for six months, while the others were given a placebo. Participants didn't know which group they were in. At the end of the experiment, the researchers measured variables including their insulin sensitivity, and participants filled out questionnaires on their weekly Sun exposure—as this can be a source of vitamin D—as well as their diet and physical activity.

5000 IU is considered a high dose, with between 600 to 4,000 IU considered safe, although it is thought some people may need to take more to prevent chronic disease.

The team found taking vitamin D improved how insulin worked in muscle tissue after six months. However, the study was limited because it only involved French Canadians, meaning the results might not relate to a wider population, the authors wrote.

Future studies could look at the mechanisms which mean people respond differently to vitamin D, and whether the changes observed would last long term, they said.

Study co-author Dr. Claudia Gagnon, assistant professor and endocrinology researcher at Université Laval in Quebec, told Newsweek: "We know that vitamin D regulates numerous genes involved in diabetes. Animal and in vitro studies have also shown that vitamin D may improve insulin secretion and insulin action directly or indirectly through reduction of low-grade systemic inflammation."

"This study is significant because it shows that vitamin D supplementation may potentially slow metabolic deterioration in individuals at high risk of diabetes or with newly diagnosed type 2 diabetes."

But she said it's not clear if patients who have had type 2 diabetes for a long period would benefit from vitamin D supplementation.

Gagnon went on to warn the study isn't a green light to take high amounts of vitamin D.

She said: "At this stage, results of our study need to be confirmed in other studies. Moreover, the safety of high-dose vitamin D supplementation (such as what was used in our study) beyond 6 months is not demonstrated. I would thus suggest at this time that current recommendation be followed."

Taking the recommended amount to promote good bone health "is important," she said.

Dan Howarth, head of care at the charity Diabetes UK, who did not work on the project, told Newsweek: "This study shows that high doses of vitamin D supplements are safe and suggests that they could alter the biology underlying Type 2 diabetes, possibly helping to improve how the body produces and uses insulin.

"However, the evidence beyond this study is mixed and more research is needed to understand if vitamin D supplements help to reduce a person's risk of Type 2 diabetes, and who would benefit most from them.

"The best way to lower your risk of Type 2 diabetes is to eat a healthy, balanced diet and be as physically active as possible. If you are following a healthy diet then vitamin supplements should not be necessary, and doing regular physical activity can also help to improve your insulin sensitivity."

Some 30 million Americans have diabetes, with between 90 to 95 percent of those dealing with type 2, according to the Centers for Disease Control and Prevention. Over the past two decades, the number of adults in the U.S. diagnosed with diabetes has more than tripled.

The cells of people with type 2 diabetes don't react correctly to insulin, a hormone which helps turn sugar into energy. This spikes their blood sugar, which can damage the body and can cause heart disease, blindness, and kidney problems if left untreated.

Depending on the severity of the condition, a person can manage their diabetes with injectable insulin or pills which help to regulate blood sugar. As obesity is a risk factor, changing one's diet has also been shown to reverse type 2 diabetes in some people. Most people have prediabetes before they develop type 2, and making lifestyle changes such as eating healthily and being physically active can stop or slow the development of type 2 diabetes.