March 3, 2003, NEW YORK – People with diabetes may be able to ward off colds and other minor infections by taking a daily multivitamin, according to a study released Monday.
Taking a vitamin and mineral supplement did not prevent infections in people without diabetes, but the study’s lead author did not rule out that some people without diabetes might see a drop in infections if they take a supplement.
“If the benefit seen in diabetics is due to the fact that their nutrition was more marginal, then any population at risk of having marginally inadequate nutrition, such as the elderly in general, might also benefit,” Dr. Thomas A. Barringer, of Carolinas Medical Center in Charlotte, North Carolina, told Reuters Health.
Noting that most of the people in the study were overweight or obese, Barringer said that “if obesity was a factor in why they benefited, then all obese people might benefit.”
Forty percent of US adults take some sort of vitamin or mineral supplement on a regular basis, but there is little scientific evidence showing that supplements actually boost health.
But some research does suggest that a multivitamin enhances immune function, Barringer noted. The elderly and people with diabetes often do not consume adequate amounts of nutrients and they also have a slightly higher risk of infection, so Barringer’s team studied whether a vitamin and mineral supplement would prevent minor infections.
A multivitamin did seem to ward off infections, at least in people with diabetes, the researchers report in the March 4th issue of the journal Annals of Internal Medicine. All the diabetic patients had type 2 diabetes, the most common form of the disease.
Only 17% of diabetics taking a multivitamin reported having an infection, such as an upper respiratory infection, the flu or a gastrointestinal infection, compared with 93% of diabetics who were taking a dummy pill. In addition, 89% of people with diabetes who took a placebo pill reported missing at least one day of work during the one-year study compared with none of the diabetics taking a multivitamin.
The reduction in infections was found almost exclusively in people with diabetes, according to the report. Participants with diabetes were more likely to be deficient in at least one vitamin or mineral at the start of the study, which could explain the beneficial effect of a multivitamin, Barringer’s team points out. The researchers are uncertain, however, whether these small differences fully explain the effect.
The study included 130 adults ages 45 and older. Roughly two out of three participants were overweight or obese and about 30% had type 2 diabetes. Although the researchers originally wanted to measure the effect of multivitamins in the elderly, too few older people enrolled in the study for them to make a conclusion. Only 33 patients were over 65.
Since most participants in the study were overweight, Barringer said it is uncertain whether people who are overweight but who do not have diabetes, or who only have diabetes but are not overweight would also benefit.
Even though Barringer cautioned that the study is not the final word on the effect of multivitamins on the immune system, he pointed out that supplements are safe and relatively inexpensive, so taking a daily multivitamin is “a reasonable option” for people who are overweight, who have any type of diabetes, who may not receive adequate nutrition or whose immune system is weak.
The study represents a step toward understanding the effects of supplements, but it has several limitations, including its small size, according to Drs. Wafaie Fawzi and Meir J. Stampfer at Harvard School of Public Health in Boston, Massachusetts.
They note that two out of three similar studies found no beneficial effect of a multivitamin when it came to preventing infections. However, those two studies were conducted in people who already had an adequate intake of nutrients before taking the supplement.
“The potential impact of supplements merits further rigorous study, especially among diabetic persons and other vulnerable populations,” they conclude in an editorial that accompanies the study.
The study was funded by an independent, charitable organization known as the Charlotte-Mecklenburg Health Services Foundation.
– Source: Reuters Health