Doctors are increasingly diagnosing people with prediabetes. These individuals have slightly elevated blood sugar levels that don’t yet meet the criteria for frank diabetes.

How Is Prediabetes Diagnosed?

A blood test called hemoglobin A1C or HbA1c measures glucose in blood over a three-month time period. When the number is consistently over 6.5%, the physician diagnoses the patient with diabetes. Someone with an HbA1c between 5.7% and 6.4% has prediabetes.

Does It Always Lead to Diabetes?

Doctors have assumed that such a diagnosis inevitably means the person will develop diabetes. However, a Swedish study shows that this is not always the case (Journal of Internal Medicine, online June 4, 2019).

In fact, a group of 918 individuals who were 60 years old or older had blood sugar in that gray zone. Of that group, 13 percent went on to develop diabetes. An additional 22 percent saw their blood sugar drop to normal. The rest stayed in the prediabetes category. While this still conveys some risk, it is not quite as dangerous as diabetes.

The lead author noted:

“Lifestyle changes such as weight management or blood pressure control may help stop prediabetes from progressing.”

Will Vitamin D Help Prevent Progression?

Researchers are interested in ways to keep this condition from progressing to outright diabetes. People with low levels of vitamin D circulating in their bloodstreams seem more susceptible to prediabetes. Will giving people vitamin D supplements reverse the problem?

A study from India suggested that those people who have low levels of vitamin D might be able to reverse prediabetes with vitamin D and calcium supplements (Diabetes Research and Clinical Practice, March 2014). Investigators randomly assigned 125 subjects with prediabetes to receive either vitamin D plus calcium or calcium alone.

Half the volunteers took vitamin D3 in doses of 60,000 International Units once weekly for eight weeks. People getting vitamin D were significantly less likely to have diabetes at the end of two years than those taking calcium alone. Although the study was small, it suggested that vitamin D supplements might reduce insulin resistance and improve blood sugar levels in people with prediabetes.

Scientists need to follow up this type of interesting research to see how well it holds up. Subsequently, a systematic review of ten randomized controlled trials found that vitamin D supplementation reduced fasting blood sugar and HbA1c (Diabetic Medicine, March 2016).

However, the investigators concluded:

“No beneficial effect of vitamin D in improving insulin resistance was identified.”

Consequently, people with elevated HbA1c measurements may want to try taking vitamin D3 supplements if their blood levels are low. They should not count on this to reverse prediabetes, however.

Other Approaches to Warding Off Diabetes:

Get Enough Magnesium:

Research suggests several possible options for keeping people diagnosed with prediabetes from actually developing diabetes. As with vitamin D, people who have low circulating levels of magnesium may be at greater risk for prediabetes (Diabetologia, May 2017). People who consume the most magnesium in their daily diets are 15 percent less likely to develop type 2 diabetes (Diabetes Care, Dec. 2017). We don’t know whether those who take supplements also benefit.

Lose Weight:

Perhaps the most promising approach is simple in concept, but difficult to accomplish. Scientists have found that people who lose weight can keep their prediabetes from progressing (Diabetic Medicine, March 2019).

Consider Taking Citrus Flavonoids:

Beyond that, a single randomized controlled trial of citrus flavonoids (Eriomen®) found that some people taking this supplement were able to reverse their metabolic condition (Phytotherapy Research, online June 11, 2019). Scientists need to do more research to confirm whether this herbal supplement is truly effective.