An estimated 79 million U.S. adults are pre-diabetic. The term "pre-diabetes" is a rather recently coined term to describe the increasingly common condition in which your blood sugar levels are chronically elevated, but you don’t have full-blown diabetes yet. The goal of treating pre-diabetes is to naturally prevent or delay the onset of type 2 diabetes. The major recommendations have been weight loss, better eating habits and more physical activity. However, burgeoning research suggests that your level of vitamin D is closely related to your pre-diabetes status. It might one day become the focus of pre-diabetes treatment.
Vitamin D is both a fat-soluble vitamin and a hormone. You probably know it as the sunshine vitamin because your body can synthesize vitamin D when ultraviolet sunlight hits your skin. Inside the body, vitamin D promotes calcium absorption, so it’s mainly known as an important protector of bone health. It’s also central to cell growth, immune function and inflammation control. Over the past 20 years, however, a growing body of research has revealed many other roles for vitamin D, including heart health, as well as controlling high blood pressure, obesity and diabetes. Researchers have discovered that vitamin D receptors are located all over your body, including in the pancreas, which produces insulin and is a key player in the onset of diabetes.
Pre-diabetes happens when your blood sugar levels are consistently higher than normal, but don’t yet reach the level at which you’d be diagnosed with diabetes. Doctors and scientists also refer to this condition as impaired glucose tolerance. Based on CDC data of a representative sample’s A1c levels, approximately 35 percent of U.S. adults are pre-diabetic. Being pre-diabetic naturally increases your risk for type 2 diabetes, but at the pre-diabetic stage, many people are already experiencing the heart-related complications of diabetes, along with increases in blood lipids such as cholesterol. Most people with pre-diabetes develop full diabetes within 10 years, but the National Diabetes Education Program reports that losing 5 to 7 percent of your body weight can prevent the disease.
Vitamin D Deficiency Linked to Pre-Diabetes
Elena Barengolts, an endocrinologist with the University of Illinois-Chicago published a meta-analysis of research in the journal “Endocrine Practice” linking vitamin D and pre-diabetes. She found that most pre-diabetics are vitamin D-insufficient. Too little circulating vitamin D is defined as a concentration of less than 30 ng/mL, and estimates are that 77 percent of the U.S. population falls below this level. People with low vitamin D status tend to have higher fasting blood sugar levels, impaired glucose tolerance, higher rates of metabolic syndrome and a higher incidence of pre-diabetes. Her findings suggest that supplementation with vitamin D among pre-diabetics improves insulin secretion, insulin sensitivity and insulin resistance.
Current Intake Recommendations
Restoring pre-diabetics’ vitamin D stores to normal, healthy levels might be an important part of preventing type 2 diabetes, Barengolts writes. More research is needed to confirm this and provide specific, evidence-based recommendations. In the meantime, many groups of American adults and children get too little vitamin D. The Dietary Guidelines for Americans 2010 labels vitamin D as a “nutrient of concern” because intake is so low, health problems are possible. The Institute of Medicine recommends that from the age of 1 until age 70, all Americans need to consume at least 15 mcg of vitamin D daily. After that, you need 20 mcg daily. Salmon, mackerel, tuna, milk and yogurt are good sources of vitamin D, along with cod liver oil.
- CDC: National Diabetes Fact Sheet -- Diabetes Definitions
- "Endocrine Practice"; "Vitamin D Role and Use in Prediabetes"; Elena Barengolts; May-June 2010
- National Diabetes Education Program; "Small Steps. Big Rewards -- Your Game Plan to Prevent Type 2 Diabetes: Information for Patients"; July 2006
- "Diabetes Forecast"; "Vitamin D and Diabetes"; Andrew Curry; October 2009
- "Archives of Internal Medicine"; "Prevalence of Cardiovascular Risk Factors and the Serum Levels of 25-Hydroxyvitamin D in the United States"; David Martins et al; June 11, 2008
- National Diabetes Information Clearinghouse; "Insulin Resistance and Pre-Diabetes"; October 2008