Low vitamin D levels may put people at an increased risk of getting type 2 diabetes. That's according to research undertaken by the United States based University of California (UC), and San Diego School of Medicine, in conjunction with the Seoul National University in Korea.
Published in PLoS One online scientific journal, the study of more than 900 individuals from southern California demonstrated that blood vitamin D levels higher than 30 ng/mL was associated with a considerable reduction in the risk of being diagnosed with type 2 diabetes.
Type 2 diabetes occurs when the body cannot produce enough insulin or is unable to use insulin effectively. Vitamin D metabolites – small molecules that are by-products of metabolism – stimulate the pancreas to produce insulin, therefore may protect against the development of type 2 diabetes, the research suggests.
The researchers found that participants with blood levels of the active form of vitamin D above 30 ng/mL had a 70% lower occurrence of diabetes, compared with those whose levels were less than 30 ng/mL.
Jean Hailes for Women's Health Head of Education & Knowledge Exchange, Chris Enright, said the research is important in adding to what we know about for preventing type 2 diabetes.
"Diabetes is the fastest growing chronic condition in Australia with one person diagnosed every five minutes," said Ms Enright.
Type 2 diabetes accounts for 85% of the 1.7 million Australians who have diabetes. In light of the looming epidemic, Ms Enright said investigations such as those carried out in this study were "crucial for identifying ways to prevent type 2 diabetes."
The researchers noted that although further research is needed to prove that high vitamin D levels can prevent type 2 diabetes, this study and past research demonstrates a strong association between higher blood levels of vitamin D and a reduced risk of type 2 diabetes.
One study, which was conducted in mice, showed that higher rates of diabetes were observed in mice lacking vitamin D receptors on their cell. A receptor is a protein that receives chemical signals to convey messages within the cell's environment. Other studies have shown the presence of vitamin D receptors on insulin-producing cells in the pancreas appears to stimulate the production of insulin.
For most Australians, the main source of vitamin D is through sun exposure as vitamin D is made naturally in the skin this way. Getting the right amount of sun exposure for healthy vitamin D levels can be as easy as getting a few minutes of mid-morning or mid-afternoon sun exposure to arms and hands on most days of the week, for most people.
The body also obtains vitamin D from some natural foods (eg, tuna, mackerel, salmon), fortified foods (eg, dairy products, orange juice, soy milk, cereal), and dietary supplements.
Looking to the future, Ms Enright said that "we may well see vitamin D included as part of a prevention strategy."
In the meantime, she said that because type 2 diabetes results from a mixture of genetic and modifiable risk factors, "people can look at addressing the modifiable factors."
Key modifiable risk factors include high blood pressure, being overweight or obese, insufficient physical activity and poor diet.
Ms Enright said people can reduce their risk of getting type 2 diabetes, "by maintaining a healthy weight, undertaking regular physical activity, enjoy a balanced eating plan, not smoking, and ensuring blood pressure and cholesterol levels are in the normal range."
If unsure about whether at risk or how to reduce your risk, Ms Enright concluded by saying "checking in regularly with your doctor is a good way to monitor your risk factors and to learn more about how to improve your health."