About 40 percent of us take vitamin supplements regularly, according to the U.S. Centers for Disease Control and Prevention. We spend about $1.5 billion each year on them. And about 20 percent of us take a combination vitamin and mineral pill.
The minerals might be more critical.
In spite of these large numbers, until now there has little evidence that these pills do any good. Joanne Larsen’s Ask the Dietitian site is typical in her distain. “For what some people spend on vitamin and mineral supplements, that is some pretty expensive urine,” she writes.
The problem seems to be that the scientists were just not studying the right people. Those with the right stuff, in terms of vitamin and mineral supplements anyway, are people with diabetes.
Now, researchers at two universities in North Carolina—the University of North Carolina School of Medicine and Wake Forest University School of Medicine—studied two groups of people who have less than optimal nutrient intake or who have slightly higher risks of various infections. They focused on the eldery and people with type 2 diabetes to see what effect a vitamin and mineral supplement had on the rate and severity of minor infections.
The study determined that a daily multivitamin and mineral supplement can have a tremendous difference in the number of infections suffered by people with type 2 diabetes. The numbers are astounding. Only 17 percent of the people with diabetes in the study reported an infection, while 93 percent of those receiving a placebo did. Similarly, 89 percent of people with diabetes in the placebo group reported one or more absentee days compared with 0 percent of people with diabetes in the treatment group. On the other hand, the elderly—healthy adults aged 45 or older—had no benefit at all.
The study design was a randomized, double-blind, placebo-controlled trial. That’s the gold standard. But it was a small study of 158 people, 130 of whom completed the 12-month trial. People with diabetes accounted for 51 of the 130 who were studied for a year.
Participants in the treatment group received a daily pill that had amounts of vitamins and minerals very similar to those found in most commercially available multivitamin and mineral supplements. I compared the amounts used in the study to those in “Centrum,” one of the best-selling brands. The study amounts of Vitamins C and E were considerably higher than in Centrum, but still less than that those recommended in the “Harvard Cocktail1” which I take. The biggest differences appeared to be in considerably higher study amounts of manganese, selenium, and chromium.
“We don’t know whether the benefit derived more from the vitamin or mineral component,” Dr. Thomas Barringer, the lead author of the study, writes me. “There is probably a little more data from the previous research in this area that the minerals might be more critical in this regard.”
The study notes that although substantial research shows that certain infections are associated with diabetes—for example, foot ulcer infections, urinary tract infections, and unusual fungal infections—little published work addresses common upper respiratory tract infections, which accounted for the largest proportion of sick days in the trial. “The type and severity of impaired immunity in diabetic persons have been studied to some extent, but scant literature exists on ways in which to improve such impairment, other than possibly by improving glycemic control. Some research [Muchová J, Liptáková A, Országhováá Z, Garaiová I, Tison P, Cársky J, et al. ‘Antioxidant systems in polymorphonuclear leucocytes of Type 2 diabetes mellitus,’ Diabetic Medicine 1999;16:74-8] has suggested that antioxidant systems are impaired in diabetes, thus providing a theoretical basis for benefit from a supplement with antioxidant potential.”
Like we usually say, more research is needed. “If our results are confirmed in a larger trial, the widespread implementation of this preventive measure could have a substantial economic impact and could ease the burden of suffering in our society,” the study concludes.
In the meantime, what should people with diabetes do? “Given that vitamin/mineral supplements are inexpensive and safe,” Dr. Barringer writes me, “taking a once a day vitamin/mineral supplement would be a reasonable option for those with any type of diabetes.”
1 CAFE is the abbreviation for the Harvard Cocktail, which are the daily supplements recommended by Harvard’s Dr. Arturo Rolla. C stands for Vitamin C, 500 mg. A stands for one (baby) aspirin. F stands for folic acid or folate or Vitamin B9, 1 mg. E stands for Vitamin E, 800-800 IU. See also http://cgibin.rcn.com/johncm/cgi-bin/index.pl?Site=Supplements
This article originally appeared on Mendosa.com on March 19, 2003
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