Can a Mix of Chromium and Biotin Help Diabetics Control Blood Sugar?

Medically Reviewed by Gary D. Vogin, MD
From the WebMD Archives

Oct. 15, 2001 -- Chromium picolinate has been touted for years -- as an energy booster, and as a nutritional supplement to help people with type 2 diabetes keep their blood sugar levels under control. A new study suggests adding a vitamin called biotin to chromium picolinate may be even more helpful, although one expert is not convinced.

Among the suggested benefits: "significantly better" blood sugars, better cholesterol levels, as well as somewhat less fatigue and depression in people with type 2 diabetes, says study author James Komorowski, MS, director of research and development at Nutrition 21 in Purchase, NY.

Nutrition 21, the company that sponsored the study, also is the leading developer and marketer of chromium-based nutritional supplements.

Chromium, found primarily in organ meats and whole grains, is an essential mineral the body needs to process carbohydrates, fats, and proteins, Komorowski tells WebMD. Many Americans get less chromium than they need, and while some multivitamins contain the mineral, it's typically in very low doses. Recently, the RDA for a healthy adult was set at 35 to 40 mcg.

"Chromium is necessary for glucose metabolism, yet it is very poorly absorbed if you get it from food in the diet or vitamin supplements," says Komorowski. Only 0.5% of chromium fluoride -- a common form of chromium -- is absorbed into the bloodstream. Chromium picolinate is absorbed five to 10 times better, he tells WebMD.

People with diabetes may have much lower chromium levels in their bodies than others, Komorowski says. His company has published 11 clinical studies showing that giving diabetics extra chromium in the form of chromium picolinate helps them control blood sugar levels.

This study involved 34 people with type 2 diabetes. For 12 weeks, all got two daily servings of a nutritional shake with "moderate amounts of carbohydrates," similar to drinks marketed to diabetics, he says. During the study, participants were randomly assigned to receive either a shake containing the chromium picolinate-biotin mix or a plain shake used for comparison. Participants did not know which type of shake they were receiving.

In those who got the regular shake, a measure of blood sugar control called hemoglobin A1c "got dramatically worse," he says. However, those receiving chromium-biotin had levels that "didn't change a lot, even though they were getting that additional carbohydrate load," Komorowski tells WebMD.

A1c levels in the regular-shake group increased from 7.7% at the start to 8.8%. Those receiving the test shake did not have significant changes in their blood sugar (7.5% at the start vs. 7.8% at study's end). Fasting blood glucose levels rose from 176 to 199 mg/dl in the control group; in the treatment group, they rose from 153 to 161.

The treatment group also had less fatigue and depression, compared to the control group -- as judged from a questionnaire. A study is ongoing now at Duke University looking just at the depression issue, Komorowski says.

Biotin seems to be the key, says Komorowski. "Biotin is involved in many enzyme reactions in the body, some which are also related to blood sugar level." While researchers don't understand the exact mechanism by which it works, studies of muscle cells have shown that when chromium and biotin are present together, they have more of a response than what would be expected by adding their effects separately. "As soon as you put those two together, you get a much greater increase in glucose metabolism," he tells WebMD.

While another study showed that chromium's benefit was for people who were deficient in the mineral, Komorowski says his patients were not tested for chromium deficiency. In fact, testing has been difficult because stainless steel needles used to draw blood can contaminate blood samples. That problem has recently been corrected, so testing will yield more accurate results, he says.

His research group is now investigating the value of adding chromium picolinate-biotin mix to other foods diabetics can't eat right now, "to make them healthier products for diabetics."

An expert reviewed the study for WebMD and says he is not impressed with the findings, however.

"Intriguing study, but with some pretty massive limitations," says John Buse, MD, director of the Diabetes Care Center at the University of North Carolina at Chapel Hill.

He says he doubts that many Americans are deficient in chromium, and he doubts that chromium picolinate has any effect on blood sugar levels. "I have hundreds of patients who take five tablets a day. When I ask them if blood sugar levels are better, they say 'no.' They're not doing themselves any harm, but it's not helping either."

Buse tells WebMD that he never recommends nutritional shakes for people with type 2 diabetes. "Drinking caloric beverages is awful -- like plutonium -- for people with diabetes," because of the high-carbohydrate content, he says.

Had the researchers tested their "vitamin mix" in pill form or mixed with water, "that would be different; it might have shown that blood sugar got better," says Buse.

"All he's shown is that blood sugars got bad with plain shakes, and got only less-worse" with the chromium picolinate-biotin mix, Buse says. "It's hard to really call that a victory."

Buse says -- quite strongly -- that adding this vitamin mix to foods known to complicate diabetes, in order to sell products to these people, is not a good idea. "We don't want to encourage people with type 2 diabetes to eat more calories. They already have a weight problem. We don't want to make people believe that this nutritional supplement or chocolate cake is good for you. You could market it as the 'less-worse junk food' for people with diabetes. It may only have less impact than straight-up junk food."

Buse says that "on some level," the study "is cool." But because the number of patients is so small, "I don't think they've proven much of anything," he says, noting such a study would need "60 to 100 patients to show anything at all."

He says he is skeptical also because the study was both sponsored and performed by Nutrition 21, which has a financial interest in the results.