There seems to be no shortage of new studies linking vitamin D, the so-called “sunshine vitamin,” to positive health improvements. For example, an increased intake of Vitamin D through supplements has shown promise in improving immune response to COVID-19, mitigating cancer, and even reducing the risk of heart disease. Conversely, the epidemic of diabetes, specifically type-2 diabetes, has shown to be a rapidly accelerating risk to public health in communities across the globe. 

Researchers have often considered the interaction of vitamin D and insulin levels; however, past research has failed to find a benefit from vitamin D supplementation on insulin sensitivity–until recently. 

A Link: Two Loosely Related Pandemics 

Vitamin D deficiency and diabetes have one significant trait in common: both are pandemic.

Vitamin D deficiency is widespread. According to research, an estimated 1 billion people worldwide have low levels of the vitamin in their blood. Additionally, a 2011 study found that 41.6 percent of U.S. adults are deficient. Vitamin D deficiency also affects minority groups at a much higher rate, with 69.2 percent of Hispanics and 82.1 percent of African Americans below the baseline needed for optimal health.

An estimated 422 million individuals worldwide are affected by diabetes, making it one of the most common life-altering conditions and expected to increase prevalence. The number of those living with diabetes is expected to eclipse 642 million individuals by the year 2040. A key reason for the surge, hereditary issues, aging populations, and lifestyle decisions like heightened obesity caused by poor diet. 

Because of the soaring rates of diabetes among populations around the world, there is an increasingly urgent need to find preventative therapies and treatments to tackle this disease. So, how effective is vitamin D in the fight against diabetes?

Vitamin D’s Endocrinic Effect 

Beyond prevalence, there is a rapidly growing mass of evidence pointing to the effect of vitamin D deficiency as a contributing factor in developing both type 1 and type 2 diabetes. According to a 2011 paper by the America Diabetes Association (ADA):

The β-cell in the pancreas that secretes insulin has been shown to contain VDRs as well as the 1 alpha-hydroxylase enzyme. Evidence indicates that vitamin D treatment improves glucose tolerance and insulin resistance. Vitamin D deficiency leads to reduced insulin secretion. Supplementation with vitamin D has been shown to restore insulin secretion in animals.

The article continues with an examination of other potential mechanisms associated with vitamin D and diabetes, including the nutrient’s role in “improving insulin action by stimulating expression of the insulin receptor, enhancing insulin responsiveness for glucose transport, having an indirect effect on insulin action potentially via a calcium effect on insulin secretion, and improving systemic inflammation by a direct effect on cytokines.”

In addition to insulin response, Vitamin D also plays an essential role in:

• Supporting lung function and good cardiovascular health
• Brain, immune, and nervous system health

Recent Breakthrough: Prediabetes Treatment Via Vitamin D

Results recently published by the American Diabetes Association periodical Diabetes Care showcased a potential research breakthrough showcasing promising results of vitamin D’s use in reducing prediabetes in patients. The study, conducted in China, assessed whether vitamin D supplementation reduces the risk of type 2 diabetes mellitus (T2DM) in people with prediabetes. The study spanned eight trials and nearly 5,000  individuals. The study shows significant promise for physicians specializing in diabetes care, specifically the American Diabetes Association, which does not currently recommend vitamin D supplementation. Their findings included:

Vitamin D supplementation significantly reduced the risk of T2DM (risk ratio [RR] 0.89 [95% CI 0.80–0.99]; I2 = 0%). Benefit was found in nonobese subjects (RR 0.73 [95% CI 0.57–0.92]) but not in obese subjects (RR 0.95 [95% CI 0.84–1.08]) (Pinteraction = 0.048). The reversion of prediabetes to normoglycemia occurred in 116 of 548 (21.2%) participants in the vitamin D group and 75 of 532 (14.1%) in the control group.

In short, the meta-analysis showed that in patients with prediabetes, vitamin D supplementation reduced the risk of T2DM by 11 percent, and the risk may be further reduced by reversing prediabetes to the normoglycemic state by 48 percent.

Final Thoughts

Although the role of vitamin D in helping to regulate blood glucose remains far from fully understood, vitamin D status appears to play a role in the development and treatment of diabetes. It is possible that optimal vitamin D levels may be different for people at risk for developing diabetes, those with diabetes, and those without diabetes. This story and associated research are far from finished.  The exact mechanisms are not precise and need further investigation, plus additional long-term studies. 

Fortunately, this research does serve as an important and potentially life-saving reminder. We all need more vitamin D. Even more so, vitamin D should be supplemented safely to be effective and prevent the onset of many adverse health conditions.

Interested in learning more about your body’s nutritional needs? Have other questions for our Jacksonville, FL health and wellness team? Call us today at +1 904-724-5767 for a free phone consultation or make an appointment as soon as the next business day. 

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