June 28, 2011 (San Diego) -- Vitamin D may help prevent diabetes in people at high risk of developing the condition, researchers report.
The study does not prove cause and effect. "But if confirmed, there are huge implications because vitamin D is easy and inexpensive," Anastassios Pittas, MD, of Tufts Medical Center in Boston, tells WebMD.
The three-year study involved 2,039 people with high blood sugar levels. Their vitamin D levels were measured at the start of the study and six months, one year, two years, and three years later.
For every 5 nanograms per milliliter (ng/mL) increase in vitamin D levels, the risk of developing diabetes dropped by 8%, Pittas says. Levels of 30 or higher are considered normal.
The participants were divided into three groups. Participants in the group with the highest third of vitamin D levels (average reading of about 30 ng/mL) were 38% less likely to develop diabetes than those in the lowest third (average vitamin D level of 13 ng/mL).
A strength of the study is that vitamin D levels were measured at various time points, Pittas says. Past studies often relied on one measurement at the start of the study, which may not accurately reflect their vitamin D status over time.
The analysis also took into account a person's body weight, physical activity, and other factors known to decrease diabetes risk. Nonetheless, there could be some unmeasured variable that affected risk, Pittas says. He says a robust clinical trial in which half the people get vitamin D and half get placebo is needed to determine if supplements can stave off diabetes.
Sheena Kayaniyil, a PhD candidate at the University of Toronto, tells WebMD that her research also supports a role for vitamin D in the prevention of diabetes.
In a study of nearly 500 people at high risk of diabetes, higher vitamin D levels at the start of the study were associated with lower blood sugar levels three years later.
Higher vitamin D levels also predicted better function of the body's own insulin-producing beta cells at follow-up, she says. "Our research supports a potential role for vitamin D in the [development] of diabetes."
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.
Get the latest Diabetes newsletter delivered to your inbox!
Your level is currently
If the level is below 70 and you are experiencing symptoms such as shaking, sweating or difficulty thinking, you will need to raise the number immediately. A quick solution is to eat a few pieces of hard candy or 1 tablespoon of sugar or honey. Recheck your numbers again in 15 minutes to see if the number has gone up. If not, repeat the steps above or call your doctor.
People who experience hypoglycemia several times in a week should call their health care provider. It's important to monitor your levels each day so you can make sure your numbers are within the range. If you are pregnant always consult with your health care provider.
Congratulations on taking steps to manage your health.
However, it's important to continue to track your numbers so that you can make lifestyle changes if needed. If you are pregnant always consult with your physician.
Your level is high if this reading was taken before eating. Aim for 70-130 before meals and less than 180 two hours after meals.
Even if your number is high, it's not too late for you to take control of your health and lower your blood sugar.
One of the first steps is to monitor your levels each day. If you are pregnant always consult with your physician.
Thank you for signing up for the WebMD Diabetes Newsletter!
You'll find tips and tricks as well as the latest news and research on Diabetes.
Did You Know Your Lifestyle Choices
Affect Your Blood Sugar?
Use the Blood Glucose Tracker to monitor
how well you manage your blood sugar over time.