From Dr. Mercola:
Vitamin D is a steroid hormone that influences virtually every cell in your body, which is why maintaining a healthy level is so important. Low vitamin D levels are widely known to harm your bones, leading them to become thin, brittle, soft or misshapen.
But vitamin D is equally important for your heart, brain, immune function and much more. For example, there’s an important connection between insufficient vitamin D and insulin resistance and/or diabetes, both type 11 and type 2.
Vitamin D Deficiency May Influence Your Type 2 Diabetes Risk
According to recent research, vitamin D deficiency affects your glucose metabolism and may actually be more closely linked to diabetes than obesity. In a study of 118 people, those with low vitamin D levels were more likely to have type 2 diabetes, pre-diabetes or metabolic syndrome, regardless of their weight.
Among obese people, those without metabolic disorders had higher levels of vitamin D than those with such disorders, and among lean people, those with metabolic disorders were more likely to have low levels of vitamin D. According to one of the study’s authors:2
“The study suggests that vitamin D deficiency and obesity interact synergistically to heighten the risk of diabetes and other metabolic disorders. The average person may be able to reduce their risk by maintaining a healthy diet and getting enough outdoor activity.”
It’s not the first time vitamin D has been shown to play a role in diabetes. One Indian study found that vitamin D and calcium supplementation, in combination with exercise, can prevent pre-diabetes from progressing into full-blown diabetes.
For every unit increase in vitamin D levels, the risk of progression to diabetes in people with pre-diabetes went down by 8 percent.3
Another study4 published in 2013 found that type 2 diabetics given 50,000 IUs of oral vitamin D3 per week for eight weeks experienced “a meaningful reduction” in fasting plasma glucose and insulin. Other research showing this link includes but is not limited to the following:
Animal studies have shown vitamin D is a foundational factor necessary for normal insulin secretion5,6 and that vitamin D improves insulin sensitivity7,8 One study involving nearly 5,680 individuals with impaired glucose tolerance showed that vitamin D supplementation increased insulin sensitivity by 54 percent9 The mechanisms by which vitamin D reduces insulin resistance include its effect on calcium and phosphorus metabolism and by upregulating the insulin receptor gene10 Vitamin D May Lower Risk of Hyperglycemia in Those Taking Atypical Antipsychotics
Certain drugs can raise your risk of metabolic dysfunction. For example, statin drugs can trigger drug-induced diabetes. Atypical antipsychotics such as quetiapine, a bipolar medication, have also been linked to an increased risk of hyperglycemia and diabetes.
In the latter case, research suggests vitamin D3 may counteract these effects. As reported by The American Journal of Managed Care:11
“Atypical antipsychotics have long been associated with an increased risk of hyperglycemia — which can lead to new-onset diabetes, diabetic ketoacidosis, coma and even&hellip