Information about Diabetes and the Importance of Vitamin D

Expert tips from Christine Gerbstadt, M.D., R.D. a diabetes educator and a spokesperson for the American Dietetic Association

Woman Drinking Milk Image

Vitamin D has become a celebrity among nutrients. While it's long been known to be critical for bone health, a flurry of recent research suggests that a deficiency of D may also play a role in the development of cancer, Alzheimer's disease, heart disease, obesity—and diabetes.

A study in The Diabetes Educator concluded that adequate intake of vitamin D may prevent or reduce complications for those with type 2 diabetes; other evidence suggests that it may help your pancreas secrete the hormone insulin.

Getting Enough Vitamin D

To ensure that you are getting enough vitamin D:

Know your need.—Our bodies are designed to produce vitamin D when skin is exposed to the ultraviolet rays of the sun—hence its nickname, "the sunshine vitamin." But the risk of skin damage should rule out the sun as a primary source. Increased awareness of the sun's harmful potential, in fact, is one reason more Americans than ever are vitamin D deficient.

Obesity and kidney disease—both common in people with diabetes—also raise the risk for a D deficiency. The only way to know if you're deficient is by getting a simple blood test called the 25-hydroxy vitamin D test. It's usually included in routine blood work, but ask your doctor to make sure you're being tested.

According to current guidelines, a blood level of 20 nanograms per milliliter (ng/mL) is the minimum amount needed to keep bones healthy, but nutrition experts believe that 30 to 40 ng/mL is necessary to reap all of vitamin D's potential health benefits.

Eat fortified foods.—Vitamin D is found naturally in only a few foods (such as salmon and mackerel), so it's not that easy to get from your diet. Fortunately, several common food items are fortified with D, including milk, yogurt and many cereals. How much D you need depends on your age and risk factors.

The usual recommended dietary amount is 600 international units (IU) per day for adults up to 70 years old, and 800 IU for those 71 or older. If you are overweight or have diabetes, you'll probably require more: between 1,000 and 2,000 IU.

Seek supplements.—Eating a combination of nutritious fortified foods can supply the D you need, but it may be a good idea to take a supplement, too, especially if you don't eat much dairy. (A cup of milk, for example, has about 120 IU of vitamin D, so you'd need to drink at least three glasses per day to get enough.) Ask your doctor.

Too Much Vitamin D?

Should you worry about OD-ing on D? Probably not. While it was once believed that too much vitamin D could lead to health problems, most experts believe it is safe to take as much as 10,000 IU a day.

Vitamin D and Weight Loss

A recent study from Minnesota suggests that having adequate blood levels of vitamin D prior to starting a low-calorie weight-loss program may make the pounds fall off faster (Good news for many people with type 2 diabetes!). Researchers measured blood levels of D in 38 overweight men and women before and after they followed a reduced-calorie diet for 11 weeks. Those with adequate levels at the outset lost more weight—especially around the abdomen—than those who were deficient.

Adapted from our sister publication, Diabetes Focus Fall 2012

Publication Review By: the Editorial Staff at

Published: 15 Aug 2012

Last Modified: 11 Sep 2015